Patent Publication Number: US-2004042634-A1

Title: Referencing information in an image

Description:
CROSS-REFERENCE TO RELATED APPLIACTIONS  
     [0001] This application is related to U.S. patent application Ser. No. ______ to be assigned, filed on the same date as the present application, and entitled “SYSTEM AND METHOD FOR DATA ENCRYPTION/DECRYPTION”, docket 10016762-1, which is entirely incorporated herein by reference. 
    
    
     
       BACKGROUND  
       [0002] In digitally based image capturing devices an image or “photograph” of an object is stored in a digital data format in the memory within, or coupled to, the image capturing device. A nonlimiting example of a digital image capturing device is the digital camera that captures still images and/or video images. Captured images are stored in a memory that resides within or is coupled to the digital camera.  
       [0003] Watermarking and other information embedding techniques are known in the art for storing information in individual digital images. Such techniques allow information to be retrieved at a later time. Often, such information is used to verify the validity of the image and/or provide information of interest about the image.  
       [0004] Adding information into an image may be accomplished by altering the data of individual pixels. The term encryption, as used herein, refers to the process of altering pixel data to encrypt (add) information into the image, thereby generating an encrypted image. The term decryption, as used herein, refers to the process of decrypting (retrieving or reading) the information from the encrypted pixel data.  
       [0005] Many image encryption and decryption technologies are complex. Once implemented, some encryption techniques require a substantial amount of computational capacity and time from the processing device that encrypts and/or decrypts the image. Furthermore, when a public/private key system is employed, separate data files must be separately managed in a secure manner to prevent an unauthorized individual from having access to the keys. Keys allow only authorized persons to retrieve the information encrypted into the image. Other encryption systems may also employ separate files that must be securely communicated to the intended recipient of the decrypted image.  
       [0006] Encryption techniques, such as watermarking, alter information in selected pixels such that the altered pixels contain encryption information. The encryption information is detected electronically during decryption to retrieve the encrypted information. Such information may be used for verifying that the image has not been tampered with, forged or otherwise altered. However, the amount of information in an image that can be stored by altering a pixel is limited.  
       [0007] Also, if the pixel data is altered too greatly, the altered pixels may be detectable by a person viewing the image. Altering pixel data to a point that is discernable to a person viewing the image is particularly undesirable when important portions of the image are encrypted. Thus, the degree of allowable pixel alteration is limited to being below the visibility threshold of the person viewing the image if the image is to remain visually pleasing to the viewer after encryption.  
       [0008] Furthermore, once a pixel is altered, such as when a watermark is added, that pixel is communicated to the intended recipient in its altered form. Accordingly, if the intended recipient desires to further process the image, such as by magnification, the watermark may become visible or otherwise hinder further processing of the image. In some encryption systems, restoring the altered pixel to its original, unaltered state is impossible or very difficult to accomplish.  
       SUMMARY  
       [0009] A system and method for encrypting information into a digital image is disclosed. Briefly described, in architecture, one embodiment is a method comprising the steps of receiving information corresponding to a captured image from a photosensor; generating a first image from the received information, the first image comprised of at least a plurality of first pixels corresponding to the captured image; generating a second image from the received information, the second image having a different resolution than the first image and comprised of at least a plurality of second pixels corresponding to the captured image; selecting a plurality of encryption pixels from the plurality of first pixels, such that each one of the plurality of selected encryption pixels corresponds uniquely to one of the plurality of second pixels of the second image; and altering data of each one of the selected plurality of encryption pixels such that information of interest is encrypted into the selected plurality of encryption pixels, and such that corresponding ones of the plurality of second pixels remains unaltered so that the information of interest is determinable by comparing the encrypted pixels with the unaltered second pixels.  
       [0010] Another embodiment is a method for determining information encrypted into an image file, the method comprising the steps of accessing at least a first image corresponding to a captured image comprised of at least a plurality of encryption pixels, and a second image corresponding to the captured image comprised of at least a plurality of second pixels, the second image having a different resolution than the first image, and each one of the plurality of second pixels uniquely corresponding to one of the plurality of encryption pixels; retrieving the plurality of encryption pixels; retrieving the plurality of corresponding second pixels; determining a difference between each one of the retrieved encryption pixels and the corresponding second pixel; and determining information corresponding to the determined difference. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0011] The components in the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding parts throughout the several views.  
     [0012]FIG. 1 is a block diagram illustrating one embodiment of a thumbnail information encryption system implemented in a digital image capture device.  
     [0013]FIG. 2A is a block diagram illustrating an embodiment of a thumbnail information encryption system implemented in digital camera, and another embodiment of the thumbnail information encryption system implemented in a personal computer.  
     [0014]FIG. 2B is a block diagram illustrating a pixel location table  258  residing in memory  216  of digital camera  102 .  
     [0015]FIG. 3A is a block diagram of selected components of an embodiment of a digital camera.  
     [0016]FIG. 3B is a block diagram illustrating a pixel location table  258  residing in memory element  302  of personal computer  202 .  
     [0017]FIG. 4 is a flowchart of a process for encrypting information into a plurality of predefined pixel pairs residing in a high resolution image and in a thumbnail image.  
     [0018]FIG. 5 is a flowchart of a process for retrieving information from a plurality of pixel pairs residing in a high resolution image and in a thumbnail image.  
     [0019]FIG. 6 is a flowchart of a process for encrypting a plurality of sequential pixel pairs residing in a high resolution image and in a thumbnail image with information.  
     [0020]FIG. 7 is a flowchart of a process for defining a plurality of pixel pairs residing in a high resolution image and in a thumbnail image based upon a predefined portion of an image file header.  
     [0021]FIG. 8 is a block diagram of selected components of an embodiment of a digital camera having camera decryption logic. 
    
    
     DETAILED DESCRIPTION  
     [0022] A system and method for encrypting a digital image and/or a thumbnail image with information of interest is described in detail below. For convenience, a “digital image” is defined herein to include any of the various forms of digital information corresponding to an image that is captured by an image capture device.  
     [0023] As described herein, information of interest, or for brevity, information, may comprise any type of information that is suitable for encryption into an image. Non-limiting examples of information include a header, a file name, image capture device settings, a date, a time, light conditions, other images, meta data or any other information of interest. As described in detail below, such information, when represented as a numerical value, is encrypted into selected encryption pixels. For example, but not limited to, a message consisting of a character string may be converted into a numerical string using a predefined character set. As another non-limiting example, a second image may be represented as a numerical string and encrypted into selected encryption pixels. Accordingly, any information that can be represented as a numerical string, described below in greater detail, may be stored in an image in accordance with this system.  
     [0024]FIG. 1 is a block diagram illustrating one embodiment of a thumbnail information encryption system  100  implemented in a digital image capture device. For convenience, one embodiment of the encryption system is implemented in a digital camera  102 . Other embodiments of the thumbnail information encryption system  100  can be implemented in any suitable image capture device, such as, but not limited to, a digital camera, a video camera, a facsimile (FAX) machine, a copy machine, a document scanner or the like.  
     [0025] Here, an image of a lady  104  is illustrated as being captured by digital camera  102 . As described in greater detail below, when light is detected by a plurality of photosensor pixel elements, light information is generated. The light information is received and processed to generate at least two captured images of the lady  104 . One image is a high resolution image  106 . Another image is a lower resolution image, referred to herein for convenience as a thumbnail image  108 . Thumbnail image  108  may be any suitable image having a relatively lower resolution than the high resolution image  106 . Preferably, the generated high resolution image  106  and the generated thumbnail image  108 , along with other information such as a file name and header information, is combined into a single file, referred to herein as an image file.  
     [0026] Digital camera  102  may include a control button  110 , a lens unit  112 , an image capture actuation button  114 , a viewing lens  116 , a power switch  118  and display  120 . Display  120  is used for previewing images prior to capturing or for viewing one or more thumbnail images  108  after image capture. For convenience of illustration, display  120  is illustrated on the top of digital camera  102 .  
     [0027] The high resolution image  106  is comprised of data from very many pixels. For example, one embodiment of digital camera  102  includes a photosensor  304  (FIG. 3A) having approximately three million pixel elements. Accordingly, the digital data in high resolution image  106  may have information corresponding to three million pixel elements. However, an image file having a high resolution image  106  with data corresponding to three million pixel elements is generally too large to be conveniently stored and/or communicated to other devices. Accordingly, the light information from the pixel elements is processed into data that corresponds to a relatively small, predefined area of the photosensor (or a predefined grouping of the pixel elements), hereinafter referred to for convenience as a pixel. For example, light information from three pixel elements (one sensitive to red light, an adjacent pixel element sensitive to green light and an adjacent pixel element sensitive to blue light) is processed into a single pixel having red, green and blue light information. Furthermore, the pixel includes location information that defines the location of that pixel on the image.  
     [0028] In some embodiments of digital camera  102 , greater numbers of pixel elements may be specified to define a pixel. For example, rather than the three pixel elements described above (one red, one green and one blue pixel elements), nine pixel elements may be specified to form a pixel (three red, three green and three blue pixel elements). Accordingly, required memory capacity for storing the high resolution image  106  when nine pixel elements are employed is reduced by approximately a third. Pixel elements can be grouped in any suitable manner, so long as the final pixel is sufficiently small to provide acceptable image resolution when the data is processed to display the captured image. One embodiment includes a feature that enables a user of the image capture device to define, by proxy, the number of pixel elements combined to form a single pixel. Here, the user specifies the desired memory size of the image file (which includes at least header information, high resolution image  106  and thumbnail image  108 ).  
     [0029] When light information received from the pixel elements is processed into pixels for high resolution image  106 , selected pixels are used to generate thumbnail image  108 . Thumbnail image  108 , accordingly, has a relatively small number of pixels (compared to high resolution image  106 ). When the thumbnail image  108  is displayed on display  120 , the relative size of display  120  is such that the thumbnail image  108  is viewed with sufficient resolution so that thumbnail image  108  is visually pleasing to the viewer. Furthermore, because the size of the data file for thumbnail image  108  is relatively small, the data for the thumbnail image can be quickly retrieved, processed and displayed on display  120 .  
     [0030] If high resolution image  106  is displayed on the display  120 , an undesirable time delay would be required to process and to display high resolution image  106 . Furthermore, a significant amount of processing capacity would be required to generate an image suitable for display on display  120 . Also, in portable embodiments of image capture devices, a corresponding amount of limited power supply (such as a battery) would be required to generate a suitable image from the data of high resolution image  106 . Thus, when a captured image is displayed on display  120 , thumbnail image  108  is retrieved from memory  302  (FIG. 3A) to save time and/or to conserve limited power resources.  
     [0031] In one embodiment, thumbnail image  108  is generated from high resolution image  106  by selecting pixels from high resolution image  106 . Accordingly, each pixel in thumbnail image  108  has a corresponding pixel in high resolution image  106 . The data for the pixel in thumbnail image  108  is the same as the data for the corresponding pixel in high resolution image  106 . Furthermore, the pixel in thumbnail image  108  is spatially related to the corresponding pixel in high resolution image  106 , as described in greater detail below.  
     [0032] In another embodiment, pixels in thumbnail image  108  and the corresponding pixel in high resolution image  106  are generated concurrently. Accordingly, as photosensor  304  is read, light information from selected pixels are used to concurrently generate a thumbnail image  108  and a high resolution image  106 . For example, one embodiment uses light information from every tenth pixel to generate thumbnail image  108 . All pixels are used to generate high resolution image  106 .  
     [0033] As described above, after thumbnail image  108  is generated, the data of the individual pixels in thumbnail image  108  is the same as the data of the corresponding pixels in high resolution image  106 . Furthermore, pixels in thumbnail image  108  are spatially related to their corresponding pixels in high resolution image  106 , as described in greater detail below.  
     [0034] Each pixel in thumbnail image  108  is spatially related to a corresponding pixel in high resolution image  106 . Thus, the relative position of a thumbnail pixel in thumbnail image  108  has the same relative position as its corresponding pixel has in high resolution image  106 . For example, the location of thumbnail pixel  122  is illustrated as having a location of 4,8 (where 4 is the horizontal direction along the x-axis, 8 is the downward vertical direction on the y-axis, the x-axis and y-axis origin at the upper left-hand corner of the image), and is denoted as “L=4” and “L=8” in FIG. 1.  
     [0035] Pixel  122  spatially corresponds to pixel  124  of the high resolution image  106 . That is, pixels  122  and  124  have the same relative position in their respective image. For example, but not limited to, thumbnail image  108  is arbitrarily illustrated as being twenty (20) times smaller, in length and in width, than high resolution image  106  in the simplified illustrative example of FIG. 1. Thus, the difference in the locations of pixels  122  and  124  differ by a factor of 20. Accordingly, the location of pixel  122 , defined as 4,8 on thumbnail image  108 , corresponds to pixel  124  having a location defined as 80,160 (where 80 is the horizontal direction along the x-axis,  160  is the downward vertical direction on the y-axis, the x-axis and y-axis origin at the upper left-hand corner of the image) on high resolution image  106 . That is, the location of pixel  122  is known relative to the location of pixel  124 . The corresponding low resolution and high resolution pixels  122  and  124  are hereinafter defined as a “pixel pair” for convenience.  
     [0036] Each of the pixels of thumbnail image  108  have a corresponding pixel in the high resolution image  106 . That is, light information from selected pixels used to generate a thumbnail image  108  has a corresponding pixel in the high resolution image  106  that comprises the same data. Generally, any pixel  126 , defined by location i, j on thumbnail image  108 , has a corresponding pixel  128  defined by a location (N×i) and (N×j) on high resolution image  106 . The term “N” above corresponds to the relative displacements between a pixel on thumbnail image  108  and high resolution image  106 . In the simplified illustrative example described above, the value of N is 20 because the x-axis value of pixel  122  is 4 and the x-axis value of pixel  124  is 80 (4×20=80). Also, the y-axis value of pixel  122  is 8 and the y-axis value of pixel  124  is 160 (8×20=160). Accordingly, pixels of thumbnail image  108  have a corresponding pixel in the high resolution image  106 . That is, for each of the pixels comprising thumbnail image  108 , a pixel pair is defined using the corresponding pixel in high resolution image  106 .  
     [0037] The location system described above is a very simplistic illustrative Cartesian coordinate system. The location of pixels in thumbnail image  108 , and its corresponding pixel location on high resolution image  106 , can be defined using any suitable coordinate system or location system. Cartesian coordinates or polar coordinates are non-limiting examples of coordinate systems that are used by embodiments of digital camera  102  (and personal computer  202 , described below in FIG. 2). Also, the relative displacement N described above was an arbitrary value selected to demonstrate the spatial relationship between a pixel in thumbnail image  108  and its corresponding pixel in high resolution image  106 . Any suitable relative displacement factor can be employed by various embodiments.  
     [0038] Furthermore, pixel  122  is illustrated as a relatively large square for convenience. A pixel is actually much smaller than the square used to illustrate pixel  122  (and other pixels described herein), and that the use of the square illustrating a single pixel is merely demonstrative.  
     [0039] One embodiment of the thumbnail information encryption system  100  is predicated on pixel  122  having data that is the same as the data for pixel  124 . Since pixel  122  and pixel  124  are comprised of the same data, and since high resolution image  106  and thumbnail image  108  are communicated together in a single image file  310  (FIG. 3A), one of the pixels of the pixel pair is selected to be the carrier of encryption information. For convenience, the pixel of a pixel pair selected to carry information is referred to herein as the encrypted pixel. Accordingly, when the image is encrypted, data for one of the pixels of a pixel pair is altered with information data referred to herein as encryption information. The other pixel of the pixel pair is not altered, and is used as a reference pixel or an unaltered pixel. Thus, when the image is decrypted, the pixel data for the two pixels of a pixel pair are compared, and the difference in the pixel data corresponds to the encrypted information.  
     [0040] Returning to the simplified illustrative example of FIG. 1, pixel  124  is arbitrarily selected as the encrypted pixel. Thus, pixel data for pixel  124  is altered by adding encryption information. Pixel  122  is the reference pixel or unaltered pixel.  
     [0041] For example, if pixel  124  contained red, green, blue data of 1,3,1 (where the red=1, green=3 and blue=1), the green value could be encrypted to carry the encryption information of 1 by altering the pixel data to 1,4,1. Thus, the green data is increased from a value of 3 to a value of 4 to carry the encryption information of 1.  
     [0042] For convenience, the above-described simplified illustrative example presents the pixel data for pixel  124  as having three base-ten numbers, each number representing a blue value, a green value and a red value. In one embodiment, the pixel data is represented as three 8-bit words, where three bits would represent each color. Thus, the red value of 1, base ten, described above would be represented as 001 with an 8-bit word. Other embodiments employ other data formats. For example, but not limited to, the pixel data may be part of a black-and-white image, where the pixel data represents grayscale data having a predefined number of bits (for example, but not limited to, two to eight bits), depending upon the embodiment. As another non-limiting example, another embodiment employs pixel data having twenty-four bits of information. Embodiments are equally applicable to any data format used to represent pixels, so long as there are two images available, a lower resolution image and a higher resolution image, such that encryption pixels from a plurality of pixel pairs are encrypted with information as described herein.  
     [0043] As described in greater detail below, a plurality of predefined pixels are selected in a predefined order for carrying encryption information. Thus, the predefined pixels can be encrypted to carry information. The manner in which pixels are selected for encryption, and the later decryption of the selected pixels, described in greater detail below.  
     [0044] For convenience, the term encryption used herein refers to the alteration of pixel data to represent at least a portion of the information. Similarly, the term decryption used herein refers to the inspection of the altered pixel data to determine the above-described portion of the information. Thus, one of the pixels in the thumbnail image  108  or the high resolution image  106  is selected for encryption, identified herein as the encryption pixel. The other pixel (not having encrypted information) is defined herein as the reference pixel.  
     [0045] In the above-described, simplified illustrative example wherein data for pixel  124  was altered from 1,3,1 to 1,4,1, the small change in the data of the encrypted pixel is not likely to be visibly discernable to an individual viewing the image. Such encryption encrypts information in the selected encryption pixels of the pixel pairs having a value such that any distortion caused by an altered pixel is not visibly discernible to an individual viewing the image. Accordingly, the individual viewing an image having information encrypted into encryption pixels, without electronic analysis of the image, would not be aware that the image has been encrypted.  
     [0046] Alternatively, the encrypted information could have a value such that the altered pixel is visibly distorted. As another simplified illustrative example, data for pixel  124  could have been changed from 1,3,1 to 1,8,1 to encrypt a value of 5 into the green data. If many encrypted pixels were thus changed, the encrypted pixels could discernibly distort the encrypted image. However, since pixel  122  (residing in the thumbnail image  108 ) has not been altered, and since the value of pixel  122  is 1,3,1 (equal to the original value of pixel  124 ), the encrypted pixel  124  can be easily restored and/or reconstructed. That is, encrypted pixel  124  can be easily restored and/or reconstructed to a pre-encryption value of 1,3,1 since the reference pixel  122  (or unaltered pixel  122 ) specifies the pre-encryption value of pixel  124 .  
     [0047] In the simplified illustrative examples described above, the green data was arbitrarily selected for altering. Any part of, or all of, the pixel data could be selected for encryption. The manner of encrypting information into a selected pixel is limitless. More significantly, because one of the pixels of a pixel pair has not been altered, the type of information embedded in an encrypted pixel is not limiting because the encrypted pixel can be restored and/or reconstructed from the reference pixel.  
     [0048] In an embodiment that encrypts pixels to an extent that the encrypted pixel is visibly distorted, a person not possessing an embodiment of a decryption system embodiment will be limited to viewing visibly distorted images since a plurality of encrypted pixels carrying information cannot be restored and/or reconstructed. However, a person possessing a valid decryption system embodiment is able to view undistorted images since encrypted pixels may be restored and/or reconstructed prior to displaying the image.  
     [0049] In another embodiment, the images are configured to automatically reconstruct prior to display, such that a viewer does not have to view a distorted image having a plurality of encrypted pixels. In this embodiment, an uninformed individual viewing the image would not be aware of the presence of encrypted information residing in the encrypted pixel. Accordingly, each image (having a thumbnail image  108  and a high resolution image  106 ) includes logic to decrypt the information and to reconstruct the encrypted pixels before the image is displayed. In one embodiment, the decryption code is included in the image file such that when the image file is opened, the encrypted pixels are automatically restored and/or reconstructed.  
     [0050] The above-described embodiment of a thumbnail information encryption system  100  is described using pixel pairs. Each pixel pair is comprised of a pixel from a thumbnail image and a high resolution image. Each pixel in a pixel pair has the same data and is spatially related. In another embodiment, the thumbnail image pixel and the high resolution image pixel have different data values, but the relationship between the pixel data of each pixel pair is known. Accordingly, when the encrypted pixel having encryption information is compared with the reference pixel, the data relationship is used to determine the data difference between the two pixels, and thereby allowing determination of the encryption information.  
     [0051] The above-described embodiment of a thumbnail information encryption system  100  is described as having one of the pixels of a pixel pair selected to receive the information. Data for the selected pixel is altered by embedding encryption information. One embodiment alters pixel data from a thumbnail image. Another embodiment alters pixel data from a high resolution image. Yet another embodiment is configured to select the encryption pixel in a predetermined manner, or even a random manner, so that parts of the encryption information is embedded in both the thumbnail image and the high resolution image.  
     [0052] Summarizing one embodiment, a pixel in thumbnail image  108  and a corresponding pixel in high resolution image  108 , are pixel pairs. Initially, data for each pixel in a pixel pair is equal (or related by a known relationship). Furthermore, the pixels are spatially related to each other. One of the pixels of a pixel pair is selected for encryption (the encrypted pixel). Data for encrypted pixel is altered, as described herein, so that the information is embedded into the selected encrypted pixel. Data for the other pixel of the pixel pair (the reference pixel or the unaltered pixel) is not altered. By selecting a plurality of pixel pairs, any desired amount and type of information is embedded into an image by altering the selected encryption pixels. The encrypted information is determined by comparing the encryption pixel with the reference pixel of each pixel pair. In one embodiment, the encryption pixel is restored and/or reconstructed using the data of the reference pixel.  
     [0053]FIG. 2A is a block diagram illustrating an embodiment of a thumbnail information encryption system  100  implemented in digital camera  102 . Another embodiment of the thumbnail information encryption system  100  is implemented in personal computer  202 . Personal computer  202  may further include, or be coupled to, a display  204 , a printing device  206 , a user interface device  208  (keyboard) and other peripherial devices (not shown). Digital camera  102  further includes at least a memory unit interface  210  and a plug-in interface  212 .  
     [0054] Personal computer  202  is configured to communicate with digital camera  102  such that digital images captured by digital camera  102  may be retrieved, encrypted and/or decrypted. Personal computer  202  includes at least a processor  214  and a memory  216 . Personal computer  202  may further include a display interface  218 , a printer interface  220 , a memory module interface  222 , a wire connector interface  224 , a keyboard interface  226  and a communication bus  228  (in addition to many other components not illustrated in FIG. 2 for convenience).  
     [0055] Memory  216  further includes a personal computer (PC) image file region  230  (where at least one image file having at least a high resolution image and a thumbnail image reside), and thumbnail decryption logic  232  resides. The PC image file region  230  and thumbnail decryption logic  232  are described in greater detail below. An alternative embodiment of personal computer includes PC thumbnail encryption logic  234 . Memory  216  may also contain other data, logic and/or information used in the operation of personal computer  202 , however such data, logic and/or information are described herein only to the extent necessary to describe thumbnail information encryption.  
     [0056] Personal computer  202  is illustrated as being coupled to a display  204 , via connection  236 , so that captured images of a high resolution image and/or a thumbnail image encrypted as described herein can be viewed on display screen  238  residing in display  204 . Personal computer  202  is further illustrated as being coupled to printer  206 , via connection  240 , so that a high resolution image and/or a thumbnail image is printed. Also, personal computer  202  is illustrated as being coupled to keyboard  208 , via connection  242 , so that an authorized individual can input relevant information regarding the encryption information and control execution of thumbnail decryption logic  232  and/or PC thumbnail encryption logic  234 .  
     [0057] Memory  216 , display interface  218 , printer interface  220 , memory module interface  222 , wire connector interface  224  and keyboard interface  226  are coupled to communication bus  228  via connection  244 . Communication bus  228  is coupled to processor  214  via connection  246 , thereby providing connectivity to the above-described components. In alternative embodiments of personal computer  202 , the above-described components are connectivley coupled to processor  214  in a different manner than illustrated in FIG. 2A. For example, one or more of the above-described components may be directly coupled to processor  214  or may be coupled to processor  214  via intermediary components (not shown).  
     [0058] For convenience, the user interface device  208  is hereinafter referred to as keyboard  208 . Other suitable user interfaces are employed in alternative embodiments such that an authorized individual can input relevant information regarding the encryption information and control execution of thumbnail decryption logic  232  and/or PC thumbnail encryption logic  234 .  
     [0059] In one embodiment of digital camera  102 , digital camera  102  transfers captured image files to personal computer  202  via a hard wire connection  248 . Connection  248  is coupled to a plug-in attachment  250 . Plug-in attachment  250  is configured to connect to plug-in interface  212 . The individual simply connects plug-in attachment  250  to plug-in interface  212  thereby establishing connectivity between digital camera  102  and personal computer  202 . The authorized individual controlling execution of the thumbnail decryption logic  232 , PC thumbnail encryption logic  234 , or other logic configured to communicate image files, then instructs personal computer  202  and/or digital camera  102  to transfer image files from digital camera  102  into the PC image file region  230 . As described above, the transferred image files include at least a high resolution image  106  and a corresponding thumbnail image  108  (FIG. 1).  
     [0060] In another embodiment, image files are stored in memory module unit  252 . When capturing images with digital camera  102 , memory module unit  252  is coupled to digital camera  102  through memory unit interface  210 , as illustrated by dashed line path  254 . Image files are transferred to personal computer  202  by removing memory module unit  252  from digital camera  102  and coupling memory module unit  252  to memory module interface  222 . Typically, a convenient coupling port or interface (not shown) is provided on the surface of personal computer  202  such that memory module unit  252  is directly coupled to personal computer  202 , as illustrated by dashed line path  256 . Once memory module unit  252  is coupled to memory module interface  222 , image files are transferred into the PC image file region  230 .  
     [0061]FIG. 3A is a block diagram of selected components of an embodiment of digital camera  102 . FIG. 3A includes selected external and internal components of the digital camera  102 , demarked by cut-away lines  300 . The internal components include at least memory  302 , photosensor  304  and camera processor  306 . In one embodiment, memory  302  further includes thumbnail encryption logic  308  and image file  310 . Image file  310  is configured to store an image file having at least a high resolution image  312 , a thumbnail image  314  and a header  316  that corresponds to a captured image.  
     [0062] Operation of digital camera  102  is initiated by actuation of power switch  118  or an equivalent device having the same functionality. Display  120  may display a view of an image currently visible through lens unit  112  and detected by photosensor  304 , referred to herein as a preview image. When digital camera  102  is displaying a preview image, digital camera  102  is referred to herein as operating in a preview mode.  
     [0063] Alternatively, an image of a previously captured image may be viewed on display  120 . When digital camera  102  is displaying a previously captured image, digital camera  102  is referred to herein as operating in a review mode. In one embodiment, as described above, the digital camera  102  displays thumbnail image  108  (FIG. 1) on display  120 . Furthermore, a menu screen may be displayed on display  120 . In one embodiment, other buttons, switches or control interface devices (not shown) are additionally configured to operate display  120  such that menu items may be selected.  
     [0064] Prior to capturing an image of an object, wherein the image is encrypted with information, the operator of digital camera  102  may visually preview the image of the object on display  120 . Or, the object may be viewed directly through the viewing lens  116 . Photosensor  304  is disposed in a suitable location behind lens unit  112  such that an image of the object is focused onto photosensor  304  for capturing. When the operator has focused the image of the object and is satisfied with the focused image, the operator actuates image capture actuation button  114  (also referred to as a shutter button or a shutter release button) to cause digital camera  102  to capture the image of the object, thus “photographing” the object. Photosensor  304  detects the image of the object through lens unit  112  and communicates digital image data corresponding to the detected image to the camera processor  306 , via connection  318 .  
     [0065] In one embodiment, the digital image data corresponding to the captured image is processed by camera processor  306  to generate an image file having at least high resolution image  312  and a thumbnail image  314 , as described herein. The digital image data is communicated to the memory  302 , via connection  320 . Accordingly, the memory element  302  is configured to store many image files  310  having a high resolution image  312  and a thumbnail image  314 . Alternatively, corresponding thumbnail images and high resolution images may be saved separately in memory element  302 .  
     [0066] In another embodiment, an image file is transferred to the memory module unit  252  (FIG. 2A). When capturing images with digital camera  102 , memory module unit  252  is coupled to digital camera  102  through memory unit interface  210 . As the user of digital camera  102  actuates image capture actuation button  114  to cause camera processor  306  to capture the current image detected by photosensor  304 , camera processor  306  communicates the image file to memory module unit  252 .  
     [0067] Accordingly, memory module unit  252  is configured to store many image files having a header, high resolution image and a thumbnail image.  
     [0068] For convenience, digital camera  102  is described above as employing both a memory element  308  and a memory module unit  252  to store image files. Preferably, digital camera  102  would, in practice, employ either memory element  308  or memory module unit  252  to store image files because employing two different and separate memory systems would be inefficient and costly. (However, it is possible some embodiments of a digital camera  102  could employ both memory element  308  and memory module unit  252 .)  
     [0069] A first encryption system and method resides in an embodiment of the thumbnail encryption logic  308  (FIG. 3B) implemented in digital camera  102 . For convenience, the first encryption system and method is described below as implemented in thumbnail encryption logic  308 . The first encryption system and method is similarly implemented in an embodiment of the PC thumbnail encryption logic  234  (FIG. 2B). Furthermore, as described herein, the encryption logic and/or the decryption logic may be implemented in other devices, such as, but not limited to, digital video cameras, FAX machines, copy machines or the like that are configured to generate image files having at least a high resolution image and a thumbnail image as described herein. Accordingly, for convenience and brevity, such other variants of the first encryption system and method (or first decryption system and method) as implemented in other devices are not described herein in detail.  
     [0070] The first encryption system and method selects pixel pairs that are to be encrypted with encryption information based upon selected portions of the image file. Thus, a predefined number of pixel pairs are used to store the encrypted information. Preferably, a large number of pixel pairs are defined such that anticipated large amounts of information can be encrypted into the encryption pixels. Thus, if the encrypted information does not require all of the predefined pixels, the unused encryption pixels are simply not encrypted with information.  
     [0071] The predefined locations are known to the thumbnail encryption logic  308  and are not easily identified, or preferably not identifiable, by an individual or code-breaking program. One pixel of each of the pixel pairs, the encryption pixel, is encoded by the thumbnail encryption logic  308  with information. Accordingly, a pixel location table  258  is employed for both encryption and decryption, where the pixel location table  258  specifies the location of at least one of the pixels of each predefined pixel pair. FIGS. 2B and 3B are block diagrams illustrating a pixel location table  258  residing in memory  216  of digital camera  102  and in memory element  302  of personal computer  202 , respectively.  
     [0072] Another embodiment only identifies pixel locations of pixels residing in thumbnail image  108  or in high resolution image  106 . Thus, since spatial relationships of the pixels of thumbnail image  108  and high resolution image  106  are known, the locations of both pixels of the pixel pair are easily determined.  
     [0073] Furthermore, one embodiment is configured to recognize that when a predefined number of encryption pixels that are unaltered (encryption pixel data matches the reference pixel data), the end of the information is recognized such that the decryption process may stop. For example, but not limited to, ten successive unaltered encryption pixels are predefined to signal the end of the encrypted information. Thus, if the information occasionally contains null data (such that an encryption pixel is unaltered), the decryption program will not misinterpret the null data as an end of the information.  
     [0074] For example, but not limited to, the file name may be the information that is to be encrypted into the encryption pixels. An exemplary file name might be “ 1234 ” in this simplified illustrative example. Furthermore, consider a grouping of predefined pixels pairs  49 , 50  and  980 , 1000 ;  51 , 46  and  1020 , 920 ;  97 , 89  and  1940 , 1960 ; and 99,122 and 1980,2440 (with other pixel pairs also defined in the predefined group of pixel pairs).  
     [0075] Once the pixel pairs are specified from pixel location table  258 , encryption information can be embedded (encrypted) into the pixel data in any suitable manner. Since the location of the pixel pairs is coded directly into the thumbnail encryption logic  308  in one embodiment, and known from the pixel location table  258  in another embodiment, the predefined pixel pairs are secret. Furthermore, in this exemplary simplified scenario where the file name “1234” is encrypted into the encryption pixels, and since file name is likely to change with each image file, the encrypted file name uniquely identifies an image file because the file name is unique to each image file. Thus, a level of image security may be provided.  
     [0076] Continuing with the simplified encryption example where the file name “1234” is encrypted into pixel pairs 49,50 and 980,1000; 51,46 and 1020,920; 97,89 and 1940,1960; and 99,122 and 1980,2440, the information having four elements can be easily embedded into the selected encryption pixels (which may be either the thumbnail image pixel or the high resolution image pixel). Furthermore, let the selected encryption pixels be from the high resolution image (HRIP) pixels and have the values as shown in Table 1 below. Also, assume the green pixel value is altered when the encryption information is embedded into the encryption pixel. Thus, the thumbnail image pixel (TIP) values are not altered.  
               TABLE 1                          Simpified Encryption Scheme                                 Before   After               Encryption   Encryption   Difference                                     Location   TIP   HRIP   TIP   HRIP   in                                         TIP   HRIP   Value   Value   Value   Value   Value                                                 49, 50    980, 1000   100   100   100   110   1       51, 46   1020, 920    102   102   102   122   2       97, 98   1940, 1960   140   140   140   170   3        99, 122   1980, 2440   821   821   821   861   4                  
 
     [0077] Table 1 illustrates that in the simplified example, the file name “1234” is encrypted into the green value (of the red, green, blue pixel values) of the encryption pixel, where the encryption pixel was selected from the high resolution image  106 .  
     [0078] One embodiment correlates the information encrypted into the encryption pixels with a predefined character code set. Such a predefined character code set may be based upon an industry standard, such as, but not limited to, the ASCII character codes. Alternatively, the predefined character set could be specially designed and incorporated as part of the code of the thumbnail encryption logic  308 .  
     [0079] For example, the character “)” may be included within a portion of the information. The character “)” has the ASCII character code of 41. The character code of 41 for the character “)” is discussed as a decimal number for convenience to facilitate the present disclosure. The character codes are preferably represented as binary numbers rather than decimal numbers. For example, the decimal number 41 can be represented as the eight bit binary number 00101001. In one embodiment, eight pixels are selected to store the binary number 00101001. In another embodiment, the red, green and blue color bits may be used to store information. For example, but not limited to, if a pixel employs eight bits, the decimal number 41 can be stored into one encryption pixel. If encryption pixels employ more bits (or less bits), then multiple numbers, and/or parts thereof, may be encrypted into the encryption pixels. The manners in which bits of an encryption pixel are encrypted with information is nearly limitless because the information is always determinable when an encryption pixel is compared with a reference pixel.  
     [0080] The simplified example above defined pixel locations in the thumbnail image based upon a simplified Cartesian coordinate system, where a pixel location is defined by a y-axis location and an x-axis location. Other embodiments use any suitable location definition systems, such as, but not limited to, a polar coordinate system.  
     [0081] When an image file is communicated to personal computer  202  (FIG. 2), as described above, an embodiment stores the image file in the PC image file region  230  of memory  216 . Thumbnail decryption logic  232  is executed to retrieve the encrypted information. Since the thumbnail decryption logic  232  knows the predefined pixel pairs used to store the encrypted information, the encrypted encryption pixels are retrieved and compared with the reference pixel of the pixel pair. For example, and in reference to Table 1 above, the encrypted pixel from the high resolution image  106  in the 980,1000 location is retrieved (having a value of 110). Also, the corresponding reference pixel from the thumbnail image  108  in the 49,50 location is retrieved (having a value of 100). The green data is compared, indicating a difference of 1.  
     [0082] Thus, part of the information (having a value of 1) is determined. Similarly, the other three pixel pairs are evaluated, such that the encrypted information, the file name, of “1234” is determined.  
     [0083]FIG. 4 is a flowchart  400  of a process for encrypting information into a plurality of predefined pixel pairs residing in a high resolution image  106  and in a thumbnail image  108  with an embodiment of the image capture device  102  of FIGS.  1 - 3 . Flowchart  400  shows the architecture, functionality, and operation of one implementation of thumbnail information encryption system  100  configured to encrypt information into a plurality of predefined pixel pairs residing in a high resolution image  106  and in a thumbnail image  108 . In this regard, each block represents a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of the order noted in FIG. 4. For example, two blocks shown in succession in FIG. 4 may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved, as will be further clarified hereinbelow.  
     [0084] The process starts at block  402 . At block  404 , the image capture device  102  captures an image of the object of interest. At block  406 , light information corresponding to the captured image of the object is received such that an image file is generated having at least a thumbnail image and a high resolution image. At block  408 , information that is to be encrypted is defined. At block  410 , the encryption pixels from the defined plurality of pixel pairs are retrieved. At block  412 , the retrieved encryption pixels are encrypted with the information.  
     [0085] At block  414 , a determination is made whether to encrypt another captured image with information. If so (the YES condition), the process returns to block  404 .  
     [0086] If not (the NO condition), the process ends at block  416 .  
     [0087]FIG. 5 is a flowchart  500  of a process for retrieving information from a plurality of pixel pairs residing in a high resolution image  106  and in a thumbnail image with an embodiment of personal computer  202  of FIG. 2. Flowchart  500  shows the architecture, functionality, and operation of one implementation of thumbnail decryption logic  232  configured to retrieve (decrypt) information from a plurality of pixel pairs residing in a high resolution image  106  and in a thumbnail image  108 . In this regard, each block represents a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of the order noted in FIG. 5. For example, two blocks shown in succession in FIG. 5 may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved, as will be further clarified hereinbelow.  
     [0088] The process starts at block  502 . At block  504 , an encrypted image file having at least a thumbnail image and a high resolution image is retrieved from a memory. At block  506 , a plurality of predefined pixel pairs having the encrypted information is identified.  
     [0089] At block  508 , the identified plurality of encrypted encryption pixels are retrieved. At block  510 , the corresponding reference pixels of each pixel pair are retrieved. At block  512 , for each pixel pair, a comparison is made to determine the difference in the data between the encryption pixel and the reference pixel. At block  514 , the information is determined based upon the difference between the data of the pixels in the retrieved pixel pairs.  
     [0090] Preferably, in one embodiment, at block  516 , the encryption pixels are restored and/or reconfigured to their pre-encryption value. The pre-encryption value of an encryption pixel is determined as described above using the reference pixel data. An alternative embodiment may omit block  516  if the encrypted pixels have been altered such that the altered pixel, when displayed, is not visibly discernible to a viewer of the image, or if it is desirable to have the pixel distortion viewed by a viewer of the encrypted image.  
     [0091] At block  518  the information retrieved from the encrypted pixels is assembled and communicated. In one embodiment, the information is communicated into a memory for later retrieval by the user. In another embodiment, the information is communicated to the user in a suitable format, such as in a visual form for printing on printing device  206 , and/or for display on display  204  (FIG. 1)  
     [0092] At block  520 , a determination is made whether information encrypted into another image is to be retrieved. If not (the NO condition), the process ends at block  522 . If at block  520  if information is to be retrieved from another image (the YES condition), the process returns to block  504 .  
     [0093] A second encryption system and method resides in another embodiment of the thumbnail encryption logic  308  (FIG. 3A) implemented in digital camera  102 . For convenience, the second encryption system and method is described below as implemented in the thumbnail encryption logic  308 . The second encryption system and method is similarly implemented in an embodiment of the PC thumbnail encryption logic  234  (FIG. 2A). Furthermore, as described herein, the encryption logic and/or the decryption logic may be implemented in other devices, such as, but not limited to, digital video cameras, FAX machines, copy machines or the like that are configured to generate image files having at least a high resolution image and a thumbnail image as described herein. Accordingly, for convenience and brevity, such other variants of the second encryption system and method (or second decryption system and method) as implemented in other devices are not described herein in detail.  
     [0094] The second encryption system and method encrypts the information into pixels as they are read from an image pixel. In the above-described simplified example where the information “1234” is encrypted into the encryption pixels, the “1” is encrypted into the first encryption pixel. The “2” is encrypted into the second encryption pixel. The “3” is encrypted into the third encryption pixel and the “4” is encrypted into the fourth encryption pixel. Thus, all pixels pairs in an image file may be used to encrypt information. Accordingly, very large information files may be encrypted into the image.  
     [0095] The second encryption system and method is configured to recognize that when a predefined number of encryption pixels that are unaltered (encryption pixel data matches the reference pixel data), the end of the information is recognized such that the decryption process may stop. For example, but not limited to, ten successive unaltered encryption pixels are predefined to signal the end of the encrypted information. Thus, if the information occasionally contains null data (such that an encryption pixel is unaltered), the decryption program will not misinterpret the null data as an end of the information.  
     [0096] Another embodiment encodes and end of file marker or code into the image at the end of the information file. Thus, upon completion of the process of encrypting the information into the image file, the next encryption pixel (or pixels if the end of file marker or code requires a plurality of encryption pixels) is encrypted with the end of file marker or code.  
     [0097] Another embodiment predefines the pixel pair (or a pixel in either the high resolution image or the thumbnail image) that will locate the first encryption pixel in which the information will be stored. Thus, the encryption pixels following the predefined encryption pixel, will be sequentially encoded with the information. This predefined first encryption pixel will also be known to the decryption program. Furthermore, if the pixel data is altered such that the altered pixel data is not discernable to a viewer, and if the first encryption pixel location is kept secret, the information may be secretly encoded into the image.  
     [0098]FIG. 6 is a flowchart  600  of a process for encrypting a plurality of sequential pixel pairs residing in a high resolution image  106  and in a thumbnail image  108  with information with an embodiment of the image capture device  102  of FIGS.  1 - 3 . Flowchart  600  shows the architecture, functionality, and operation of one implementation of thumbnail information encryption system  100  configured to encrypt a plurality of sequential pixel pairs residing in a high resolution image  106  and in a thumbnail image  108  with information. In this regard, each block represents a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of the order noted in FIG. 6. For example, two blocks shown in succession in FIG. 6 may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved, as will be further clarified hereinbelow.  
     [0099] The process starts at block  602 . At block  604 , the image capture device  102  captures an image of the object of interest. At block  606 , light information corresponding to the captured image of the object is received such that an image file is generated having at least a thumbnail image and a high resolution image. At block  608 , a first encryption pixel is retrieved. As described above, the location of at least one of the first encryption pixels is the first pixel, or in another embodiment, is specified.  
     [0100] At block  610 , the first encryption pixel is encrypted with a portion of the information. At block  612 , the next encryption pixel is retrieved. At block  614 , the next encryption pixel is encrypted with the next portion of the information.  
     [0101] At block  616 , a determination is made whether the information has been completely encrypted into the image. If not (the NO condition), the process returns to block  612 . The process of blocks  612  through  616  repeats until the information is completely encrypted into the image. If the information has been completely encrypted into the image (the YES condition), the process proceeds to block  618 .  
     [0102] At block  618 , preferably, an end of file code (or marker) is encrypted into a subsequent encryption pixel. Alternatively, no end of file code (or marker) is encrypted such that during decryption, a series of unaltered encryption pixels will signal the end of the information. The process proceeds to block  620 .  
     [0103] At block  620 , a determination is made whether to encrypt another captured image. If so (the YES condition), the process returns to block  604 . If not (the NO condition), the process ends at block  622 .  
     [0104]FIG. 7 is a flowchart  700  of a process for defining a plurality of pixel pairs residing in a high resolution image  106  and in a thumbnail image  108  based upon a predefined portion of an image file header with an embodiment of personal computer  202  of FIG. 2A. Flowchart  700  shows the architecture, functionality, and operation of one implementation of thumbnail decryption logic  232  configured to define a plurality of pixel pairs residing in a high resolution image  106  and in a thumbnail image  108  based upon a predefined portion of an image file header, and the decryption of information from selected encryption pixels. In this regard, each block represents a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of the order noted in FIG. 7. For example, two blocks shown in succession in FIG. 7 may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved, as will be further clarified hereinbelow.  
     [0105] The process starts at block  702 . At block  704 , an encrypted image file having at least a thumbnail image and a high resolution image is retrieved from a memory. At block  706 , the first pixel pair is retrieved. Depending upon the embodiment that encrypted the information into the image, the first pixel retrieved from the encrypted image will have the first information portion. In another embodiment, the thumbnail decryption logic  232  will know which pixel is the predefined first encryption pixel.  
     [0106] At block  708 , the pixels of the first pixel pair are compared. The difference in the data for the first pixel pair determines the first information portion, as indicated at block  710 .  
     [0107] At block  712 , the next pixel pair is retrieved. At block  714 , the pixels of the next pixel pair are compared. The difference in the data for the next pixel pair determines the next information portion, as indicated at block  716 .  
     [0108] At block  718 , the next pixel pair is retrieved. Here, the next pixel pair is the pixel pair following the pixel pair retrieved at block  712 . At block  718 , a determination is made whether the information has been completely decrypted from the encrypted image, as indicated by the detection of an end of file code (or marker). In another embodiment, a predefined number of unaltered encryption pixels are detected to determine that the all of the information has been decrypted from the image. If not (the NO condition), the process returns to block  714 . The process of blocks  714  through  720  repeats until the information is completely decrypted from the image.  
     [0109] Preferably, in one embodiment, at block  722 , the encryption pixels are restored and/or reconfigured to their pre-encryption value. The pre-encryption value of the encryption pixels is determined as described above using the reference pixel data. An alternative embodiment may omit block  722  if the encrypted pixels have been altered such that the altered pixel, when displayed, is not visibly discernible to a viewer of the image, or if it is desirable to have the pixel distortion viewed by a viewer of the encrypted image.  
     [0110] At block  724  the information retrieved from the encrypted pixels is assembled and communicated. In one embodiment, the information is communicated into a memory for later retrieval by the user. In another embodiment, the information is communicated to the user in a suitable format, such as in a visual form for printing on printing device  206 , and/or for display on display  204  (FIG. 1). The process ends at block  726 .  
     [0111] In an alternative embodiment, a determination is made whether information encrypted into another image is to be retrieved. If not, the process ends at block  726 . If information is to be retrieved from another image, the process returns to block  704 .  
     [0112] When an image is captured by digital camera  102 , or another suitably configured image capture device, pixels residing in photosensor  304  (or a photosensor if implemented in another image capture device) communicate light information to camera processor  306  (or a processor device if implemented in another image capture device). In one embodiment, the above-described encryption of the encryption pixels is implemented concurrently with the generation of the high resolution image  106  and the thumbnail image  108 .  
     [0113] In another embodiment, encryption of the encryption pixels occurs after an image file has been generated. Thus, light information from the photosensor  304  is received and an image file having at least a header, a high resolution image and a thumbnail image is generated. After the image file is generated, an embodiment performs the above-described encryption of the encryption pixels.  
     [0114] In one embodiment, a suitable controller, such as, but not limited to, control button  110 , is actuated to cause digital camera  102  to operate in a thumbnail information encryption mode. Accordingly, a subsequently captured image is then encrypted. Digital camera  102  remains in the thumbnail information encryption mode until control button  110  is actuated a second time, or until digital camera  102  is deactivated (shut off).  
     [0115] Alternatively, digital camera  102  may be configured to capture only the next image in the thumbnail information encryption mode, with an automatic return to a non-encryption mode of operation after the next image is captured. Thus, each image that is to be encrypted is identified by actuation of control button  110 .  
     [0116] The above-described controller may be any suitable actuating device configured to at least allow a user to cause encryption of an image file. Examples of control button  110  include, but are not limited to, a push-button, a toggle-switch, a multi-position sensing device configured to sense a plurality of switch positions, a touch sensitive device or a light sensitive device. In one embodiment, the control button  110  is a multifunction controller configured to at least cause the digital camera  102  to operate in a thumbnail encryption mode of operation. Furthermore, the controller may be implemented as a menu screen displayed on display  120  and configured to cause digital camera  102  to operate in a thumbnail encryption mode of operation.  
     [0117] Various embodiments of the thumbnail decryption logic  232  (FIG. 2A) residing in personal computer  202  were described above. FIG. 8 is a block diagram of selected components of an embodiment of a digital camera  802  having camera decryption logic  804 . The camera decryption logic  804  is configured to decrypt image files that have been encrypted in accordance with the above-described embodiments of the thumbnail information encryption system  100 . Thus, a user of digital camera  802  may retrieve, from a remote memory, an encrypted image file. Accordingly, the retrieved information is then displayed on display  120 .  
     [0118] Any of the above-described encryption processes may also be implemented in a similar manner in personal computer  202  or in another suitably configured image capture device. For example, but not limited to, PC thumbnail encryption logic  234  may reside in memory  216  (FIG. 2A). Accordingly, image files having at least a thumbnail image and a high resolution image are retrieved from the PC image file region  230 . The retrieved image file is encrypted with information of interest. Such encryption process are exemplified in the flow charts  400  and  600  of FIGS. 4 and 6, respectively.  
     [0119] Furthermore, an image file from another device or memory can be retrieved and encrypted. A conventional digital camera may employ a memory module unit  252  where the image file is retrieved from. Or, the conventional digital camera could be coupled to personal computer  202  and the image file retrieved from a memory residing in the digital camera. Or, the image file could be retrieved from a remote memory via the Internet. Or, the image file could be retrieved from another suitable computer-readable memory medium. The computer-readable medium can be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples (a nonexhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic, compact flash card, secure digital, or the like), a random access memory (RAM) (electronic), a read-only memory (ROM) (electronic), an erasable programmable read-only memory (EPROM, EEPROM, or Flash memory) (electronic), an optical fiber (optical), and a portable compact disc read-only memory (CDROM) (optical).  
     [0120] The information encrypted into a plurality of encryption pixels may be retrieved from any suitable source. For example, predefined information may be retrieved from a memory. Or, information may be retrieved from a device within the image capture device, such as a controller that determines exposure settings, a clock that determines time, or the like. Or, information may be provided from a character selection system. Examples of a character selection system include, but are not limited to, a menu configured to specify letters, a keyboard device, or a suitably configured controller such as control button and/or switch. Or, the information may be a previously captured image, watermark, logo or the like residing in a memory. Accordingly, embodiments are not limited as to the source of the information that is encrypted into the encryption pixels.  
     [0121] Furthermore, if the information is not originally provided in a form that is suitable for direct encryption into the encryption pixels, a conversion system or method may be included in an embodiment of the PC thumbnail encryption logic  234  and/or the thumbnail encryption logic  308 . For example, but not limited to, information corresponding to a character string is converted into a suitable binary number string by one embodiment such that the binary numbers corresponding to the character string are encrypted into the encryption pixels. Furthermore, a corresponding conversion program associated with the thumbnail decryption logic  232  is configured to convert the information retrieved from the encryption pixels back into the format of the originally encrypted information. Accordingly, embodiments are not limited as to the type(s) and/or nature of the conversion program(s) used to convert received information into data suitable for encrypting into the encryption pixels and/or used to convert retrieved information from the encryption pixels.