Patent Publication Number: US-8973844-B2

Title: Information exchange using photo camera as display for color space encoded image

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is related to the following applications: 
     U.S. patent application Ser. No. 13/836,447, filed concurrently herewith and entitled “Data Storage and Exchange Device For Color Space Encoded Images;” 
     U.S. patent application Ser. No. 13/842,932, filed concurrently herewith and entitled “Broadcasting Independent of Network Availability Using Color Space Encoded Image;” 
     U.S. patent application Ser. No. 13/837,155, filed concurrently herewith and entitled “Image Encoding and Decoding Using Color Space;” 
     U.S. patent application Ser. No. 13/837,895, filed concurrently herewith and entitled “Color Restoration for Color Space Encoded Image;” 
     U.S. patent application Ser. No. 13/842,856, filed concurrently herewith and entitled “Two-Level Error Correcting Codes for Color Space Encoded Image;” 
     U.S. patent application Ser. No. 13/843,111, filed concurrently herewith and entitled “Frame of Color Space Encoded Image for Distortion Correction;” 
     U.S. patent application Ser. No. 13/843,132, filed concurrently herewith and entitled “Information Exchange Display Using Color Space Encoded Image;” 
     U.S. patent application Ser. No. 13/841,338, filed concurrently herewith and entitled “Information Exchange Using Color Space Encoded Image;” 
     U.S. patent application Ser. No. 13/844,184, filed concurrently herewith and entitled “Large Documents Using Color Space Encoded Image;” 
     U.S. patent application Ser. No. 13/844,207, filed concurrently herewith and entitled “Combination Book With E-Book Using Color Space Encoded Image;” 
     U.S. patent application Ser. No. 13/837,769, filed concurrently herewith and entitled “Image Fragmentation for Distortion Correction of Color Space Encoded Image;” 
     U.S. patent application Ser. No. 13/844,000, filed concurrently herewith and entitled “Book Using Color Space Encoded Image;” 
     U.S. patent application Ser. No. 13/844,127, filed concurrently herewith and entitled “Data Backup Using Color Space Encoded Image;” 
     U.S. patent application Ser. No. 13/844,168, filed concurrently herewith and entitled “Self-Publication Using Color Space Encoded Image;” and 
     U.S. patent application Ser. No. 13/840,504, filed concurrently herewith and entitled “Information Broadcast Using Color Space Encoded Image.” 
     FIELD OF THE DISCLOSURE 
     The present disclosure relates to a data storage and exchange device for color space encoded images, and methods of encoding and decoding color space encoded images. More particularly, the present disclosure relates to encoding and decoding of machine-based data using high capacity multi-colored composite two-dimensional pictures having different symbols organized in specific order and sets in a color space. 
     BACKGROUND 
     With smartphones and tablets having become widely deployed as well as 3G and Wi-Fi based access to Internet, data capture technologies work as an interface between databases and user devices. Example data capture technologies include bar codes, QR codes, Radio Frequency Identification (RFID) and Near Field Communication (NFC). Most of these technologies are used as either a visible or an invisible tag to connect these databases and user devices. The introduction of cloud storage adds extended use of data exchange between data storage and end user devices. 
     Many households include many different devices simultaneously connected to Wi-Fi access points. This ubiquitous Wi-Fi usage increases electromagnetic fields around the home environment. Despite the usefulness of Wi-Fi, long term consequences for the human body and general health are not clear. 
     End user devices such as smartphones and tablets are frequently equipped with photo and/or video cameras. These cameras can be used for capturing information presented in different visual forms. The other data capture technologies descried earlier, including bar codes and especially two dimensional (2D) bar codes such as QR codes, have attracted the attention of many researchers and companies due to the potential for inexpensive operation. 
     Bar codes have been used for mobile applications to deliver a multitude of different mobile services over mobile phones and other mobile communication or computing devices. Such applications range from providing Uniform Resource Locator (URL) information to link a mobile device to the Internet, through to using a bar code as a form of e-ticket for airlines or event admissions. Hence, there is an ever growing demand for higher capacity bar codes, suited for robust application on mobile devices. Traditional approaches to higher capacity bar codes include: (i) using a colored symbol set and (ii) increasing the size of the bar code. There are known limitations for either approach, especially related to mobile devices with compromised, low resolution cameras. The traditional data capacity of 1D and 2D bar codes is severely limited. This severely limited data capacity constrains possible applications of 1D and 2D bar codes, and their primary task is simply linking camera phones to designated Web sites. Additional tasks may then be performed based on the Web site. This operation again is based on using of Wi-Fi or 3G connectivity. 
     The maximum data capacity of 2D bar codes has been improving over the recent years, resulting in the introduction of newer applications. 
     Presently, the use of color-based bar code and other symbolic encoding in color space technologies using mobile devices such as camera mobile phones has been limited by the physical size of the actual bar code symbol in relation to the information encoded within, and also by the image capturing mechanism on mobile devices to discriminate or resolve effectively a greater multitude of colors, especially under varied lighting conditions by an inexperienced, lay user. Another limiting factor has been color fidelity of hard copy output devices, such as color printers, in reproducing the true colors of such color based bar code or symbol sets in a color space. 
     While bar codes can be used to provide 2D encoded data, they have not been used to provide real storage devices and media. 
     SUMMARY 
     Embodiments of the present invention include systems, methods, and non-transitory computer program products for information exchange using color space encoded images. A color space encoded image can be displayed, for example on media such as posters, billboards, or paper, or on a display of a first device such as smartphone displays, palmtop displays, camera displays, tablet displays, or e-reader displays. A second device can acquire the displayed encoded image, for example by photographing the image. The second device can decode the color space encoded image or transfer the color space encoded image to a device that decodes the image. 
     In accordance with the disclosed subject matter, devices, methods, and non-transitory computer program products are provided for exchanging information between a camera and a device. 
     Certain embodiments include methods of exchanging information between a camera and a device. A method includes receiving, at the camera, information for exchange with the device and creating a first image encoding the information by creating colored cells within a color space to provide an encoded representation of the received information in an image by processing the received content to obtain a stream of integers, each integer in the stream of integers corresponding to a color in the color space for a cell in the image and creating one or more additional cells adjoining the encoded image. The one or more additional cells for assisting in decoding the encoded image. The method also includes displaying the first encoded image for the device to decode and in response to the displaying the first encoded image, receiving a second encoded image from the device, the second encoded image having colored cells corresponding to a stream of integers encoding a response. 
     Certain embodiments include methods of exchanging information between a camera and a device. A method includes receiving, at the device, a first encoded image from the camera the first encoded image having colored cells corresponding to a stream of integers encoding data. The method also includes decoding the first encoded image by locating the first encoded image by locating one or more additional cells adjoining the first encoded image and decoding the data based on the colored cells and the one or more additional cells adjoining the first encoded image. The method further includes determining a response to the first encoded image and creating a second image encoding the response by creating colored cells within a color space to provide an encoded representation of the response in an image by processing the response to obtain a stream of integers, each integer in the stream of integers corresponding to a color in the color space for a cell in the image and creating one or more additional cells adjoining the image, the one or more additional cells for assisting in decoding the image. The method also includes displaying the second encoded image for the camera to decode. 
     Certain embodiments include camera systems for exchanging information with a device. The camera system includes memory, storage, and at least one processor configured to receive, at the camera system, information for exchange with the device. The at least one processor is also configured to create a first image encoding the information by creating colored cells within a color space to provide an encoded representation of the received information in an image by processing the received content to obtain a stream of integers, each integer in the stream of integers corresponding to a color in the color space for a cell in the image and creating one or more additional cells adjoining the encoded image, the one or more additional cells for assisting in decoding the encoded image. The at least one processor is further configured to display the first encoded image for the device to decode and in response to the displaying the first encoded image, receive a second encoded image from the device, the second encoded image having colored cells corresponding to a stream of integers encoding a response. 
     Certain embodiments include devices for exchanging information with a camera. A device includes memory, storage, and at least one processor configured to receive, at the device, a first encoded image from the camera, the first encoded image having colored cells corresponding to a stream of integers encoding data. The at least one processor is also configured to decode the first encoded image by locating the first encoded image by locating one or more additional cells adjoining the first encoded image and decoding the data based on the colored cells and the one or more additional cells adjoining the first encoded image. The at least one processor is further configured to determine a response to the first encoded image and create a second image encoding the response by creating colored cells within a color space to provide an encoded representation of the response in an image by processing the response to obtain a stream of integers, each integer in the stream of integers corresponding to a color in the color space for a cell in the image and creating one or more additional cells adjoining the image, the one or more additional cells for assisting in decoding the image. The at least one processor is also configured to display the second encoded image for the camera to decode. 
     The embodiments described herein can include additional aspects of the present invention. For example, the device can comprise at least one of a computer, a phone, a smartphone, a palmtop device, a handheld device, a tablet, an e-reader, and a scanner. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various objects, features, and advantages of the present disclosure can be more fully appreciated with reference to the following detailed description when considered in connection with the following drawings, in which like reference numerals identify like elements. The following drawings are for the purpose of illustration only and are not intended to be limiting of the invention, the scope of which is set forth in the claims that follow. 
         FIG. 1  illustrates a system for storing, encoding, and decoding a 2D color space image in accordance with certain embodiments of the present disclosure. 
         FIGS. 2A-2B  illustrate the 2D color space encoded image in accordance with certain embodiments of the present disclosure. 
         FIG. 3  illustrates a method that the system performs for encoding an image in accordance with certain embodiments of the present disclosure. 
         FIG. 4  illustrates a method that the system performs for decoding an image in accordance with certain embodiments of the present disclosure. 
         FIG. 5  illustrates a block diagram of color calibration cells for restoration of proper color based on distinguishable color samples in accordance with certain embodiments of the present disclosure. 
         FIG. 6  illustrates a block diagram of a frame arrangement for geometrical distortion correction of an encoded image in accordance with certain embodiments of the present disclosure. 
         FIG. 7  illustrates a block diagram for frame fragmentation for distortion correction in accordance with certain embodiments of the present disclosure. 
         FIG. 8  illustrates a block diagram of image based information exchange from one device to another device in accordance with certain aspects of the present disclosure. 
         FIG. 9  illustrates a block diagram of an example of information exchange of a color space encoded image in accordance with certain embodiments of the present disclosure. 
         FIG. 10  illustrates information exchange using a photo camera to display a color space encoded image in accordance with certain embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The present systems and methods allow for use of 2D color-space codes to encode images with greater data capacity. The 2D color-space encoded images described herein can provide a wide variety of applications, regardless of network connectivity. The present systems and methods allow a sufficient amount of data or even an entire database to be encoded and placed in a storage device using the 2D images encoded and organized by color-space codes as described herein. 
     The present disclosure has utility in, for example, data back-up storage applications or data exchange using mobile devices to provide color two-dimensional pictures for processing. 
       FIG. 1  illustrates a system  100  for storing, encoding, and decoding a 2D color space image in accordance with certain embodiments of the present disclosure. System  100  includes a 2D color space image  102 . System  100  can encode any type of desired machine-based data. Non-limiting examples of machine-based data include text  104   a , books  104   b  (containing, for example, text and images), databases  104   c , photographs  104   d  or other artwork, images, video, film, or movies, music  104   e , or any other type of binary data  104   f.    
     In some embodiments, capturing of desired data can be done using a conventional camera or scanner, or a smartphone or tablet camera. 
     For example, a user can encode selected information into a 2D color-space coded image and print the image on any desired media (e.g., paper, textile, plastic, etc.). The 2D color-space coded image can also be depicted on any display, including posters, TV screens or computer monitors, as well as displayed on mobile devices such as smartphones or tablets. Digital photo cameras can be used as display devices as well. 
     Using a capturing device (e.g., a conventional camera or scanner or a smartphone or tablet camera) with an external PC or internal processor having image reading or decoding software, the image code can be decoded and the encoded data can be read. The present systems and methods allow information to be retrieved, decoded, and saved in the memory of a device or presented on a display for further use. For example, the decoded data can be read on a laptop computer  106   a  or a desktop computer  106   b , a smart phone  106   c , a photo camera  106   d , a palmtop or handheld device  106   e , or a tablet  106   f . All this can be done without manual work. No network connectivity or additional cost is required. 
     High Volume Data Storage and Exchange Device and Encoding/Decoding Methods 
     The present systems and methods relate to a data storage device for storing 2D color space encoded images, methods of encoding and decoding the 2D color space encoded images, and application of the 2D color space encoded images to data exchange. 
     More particularly, the present disclosure relates to encoding, transmission, and decoding of machine-based data using an appropriately formatted high capacity color image. The present systems and methods can be utilized, for example, for compact backup of printed materials, and/or data exchange between a color-image-displaying device and a plurality of image-reading devices. 
       FIGS. 2A-2B  illustrate the 2D color space encoded image  102  in accordance with certain embodiments of the present disclosure. As illustrated in  FIG. 2A , encoded image  102  includes a number of rectangular cells  202  of different colors. In some embodiments, encoded image  102  can include a black frame  204 , a white frame  206 , a “zebra frame”  208  having alternating colors, and color calibration cells  210 . 
       FIG. 2B  illustrates a close-up view of the black frame  204 , the white frame  206 , the zebra frame  208 , and the color calibration cells  210  in accordance with certain embodiments of the present disclosure. Black frame  204  and white frame  206  can be used for rough localization of the data image including rectangular cells  202 , determination of geometric distortion of the data image, and estimation of cell size and scale of rectangular cells  202 . Zebra frame  208  can be used for further calibration of cell size for rectangular cells  202 . Color calibration cells  210  can be used for determining a number of colors N c  used for encoding the data, and for indexing the colors to map the colors to numbers for encoding and decoding. 
     In some embodiments, rectangular cells  202  can use more than eight different colors. The number of colors can be expressed as N c , for example N c ≧8. Preferably, the number of colors is selected to be a power of two. 
       FIG. 3  illustrates a method  300  that the system performs for encoding an image in accordance with certain embodiments of the present disclosure. 
     The choice of appropriate color-difference metrics can help achieve stable color resolution for image-source media and image-reading devices. Most imaging devices operating in the visible spectrum are adapted to human eye color resolution. A color space describes color capabilities of a particular device by relating numbers to actual colors. Embodiments of the present disclosure utilize metrics based on low-cost non-Euclidean distance in red green blue (RGB) color space. 
     In some embodiments, the present system uses color space metrics which are close to Commission International de l&#39;eclairage (CIE) 1976 (L*,u*,v*) color space metrics. The CIELUV color space distributes colors roughly proportional to perceived color differences. In other embodiments, the present systems and methods are able to use any color space, including the CIE 1931 XYZ color space, CIELAB color space, and CIEUVW color space. Although embodiments of the present system are based on the CIELUV color space, according to experimentation, the color space used in certain embodiments is advantageously less sensitive to a color temperature of relevant image displaying media or device, and advantageously less sensitive to external illumination. Assuming R, G, and B are one byte (i.e., 0 . . . 255 or 0x0 . . . 0xFF) normalized intensity of red, green and blue color components correspondingly, a color difference ΔC between colors C 1 =(R 1 , G 1 , B 1 ) and C 2 =(R 2 , G 2 , B 2 ) can be given by the following equations: 
                           ⁢         r   _     =         R   1     +     R   2       2       ⁢     
     ⁢           ⁢       Δ   ⁢           ⁢   R     =       R   2     -     R   1         ⁢     
     ⁢           ⁢       Δ   ⁢           ⁢   G     =       G   2     -     G   1         ⁢     
     ⁢           ⁢       Δ   ⁢           ⁢   B     =       B   2     -     B   1         ⁢     
     ⁢       Δ   ⁢           ⁢   C     =           (     2   +       r   _     256       )     ⁢   Δ   ⁢           ⁢     R   2       +     4   ⁢           ⁢   Δ   ⁢           ⁢     G   2       +       (     2   +       255   -     r   _       256       )     ⁢   Δ   ⁢           ⁢     B   2                       Equation   ⁢           ⁢     (   1   )                 
where  r  describes an average red component value of C 1  and C 2 .
 
     The present system first receives machine data for encoding into an image. For example, the machine data can be contained in a file. The present system compresses the file (step  302 ). For example, the machine data can be compressed into a binary compressed file such as zip, rar, arc or any other archive format file. 
     The present system then determines an appropriate color encoding, illustrated by box  310 . For example, the present system maps the resulting code sequence to a stream of integers from 0 to N c −1, inclusive. Using the stream of integers, the present system creates a bitmap with frame formatting. Generation of frame formatting is described in further detail later. The present system fills the interior of the frames with color bitmap cells, encoded as described following. In some embodiments, the encoding can use error correction. A non-limiting example of error correction is the two-stage error correction described herein. In some embodiments, the encoding can use scrambling. In some embodiments, the encoding can use error correction in combination with scrambling. The present system determines the color of each cell based on the color calibration cells. The resulting encoded image can then be sent to any display, including a color printer, display, or other color image output device. 
     In some embodiments, the present system then performs a first level of error correction (step  304 ). One benefit of error correction is that the present system is able to decode an image properly, even if a portion of the image is damaged. For example, the present system can determine a header containing a cyclic redundancy check (CRC) error-detecting code, file name, format information, and sequence number (e.g., if the machine data and resulting encoded image represent only part of a larger data stream such as a video stream). In some embodiments, the present system can use any error detecting code such as repetition codes, addition of parity bits, checksums, hash functions, or more powerful error correcting codes. 
     In some embodiments, the present system can use a Reed-Solomon encoder of high order. A Reed-Solomon error correction code is a cyclic error-correcting code capable of detecting and correcting multiple errors in a bit stream. For example, the present system can use 8-bit words and blocks of size 255 bytes, if N c =16. In further embodiments, the present system can use other error-correcting codes such as low-density parity-check (LDPC) codes or turbo codes. Reed-Solomon error correction codes are capable of detecting errors, erasures, and combinations thereof. In some embodiments, a word size for this high order level of Reed-Solomon encoding can be equal to k*log 2 (N c ) rounded down, where k&gt;1. As described herein, in some embodiments the two-stage error coding can perform high order Reed-Solomon encoding in a first stage, and low order Reed-Solomon encoding in a second stage. The second stage can also include smaller words. For example, the word size can be equal to log 2 (N c ) bits, rounded down. 
     In some embodiments, the present system then scrambles the obtained code (step  306 ). For example, the resulting code can be interleaved using a predefined pseudorandom sequence. The present system scrambles the obtained code to spread out potential errors. Accordingly, the two-level error correction described herein can perform better. That is, when registering or capturing an image for decoding, there can be color distorgions due to non-uniform lighting, or damage on the media on which the image is printed. For example, the media can have spots, be wrinkled, and the like. The scrambling provides that “bad” color cells with uncertain data can be distributed uniformly (i.e., independently) into different encoding blocks, thereby decreasing the number of errors per block. Because error correction can have upper limits of correctable errors, the present spreading improves the effectiveness of the error correction. 
     In some embodiments, the present system then performs a second level of error correction (step  308 ). For example, the resulting scrambled code is encoded using a Reed-Solomon encoder with. For the second level of error correction, the word size can be selected to be smaller than the word size used in the first level of error correction. As described earlier, this two-stage error correction allows the present system to mark unrecoverable blocks of data during a first stage as erasures. The error correction described herein finds an index location of an error word inside a block, and also corrects the error word to its correct or true value. The two-stage error correction allows the present system to correct twice as many erasures as errors, as described in more detail later. 
     Registration 
     The present system is able to use any kind of high definition (HD) color registration device to register an encoded image. Non-limiting example registration devices can include a digital camera, a smartphone camera, a tablet camera, a video camera, a webcam, a scanner (to scan a hard copy image), etc. 
     Decoding 
       FIG. 4  illustrates a method  400  that the system performs for decoding an image in accordance with certain embodiments of the present disclosure. 
     Once an encoded image is registered, the present system can copy a registered image to any processing device containing a decoding module. An example processing device can include a computer, containing a decoding module with computer-readable instructions for decoding, where the computer-readable instructions are stored on a non-transitory computer storage medium, or containing hardware having hard-coded or embedded decoding instructions stored thereon. 
     Generally, decoding method  400  includes two high-level processes: (1) image recognition, and (2) two-stage Reed-Solomon decoding. In some embodiments, the present system uses Viterbi decoding as a Reed-Solomon decoder. 
     The present system locates the main frame (step  402 ). For example, the present system can locate the black frame and the white frame vertices. The present system can further determine the middles of the corresponding edges of the black frame and the white frame. If the main frame is not found (step  404 : No), the present system returns an error (step  406 ). For example, the error can be that the image cannot be decoded, or the error can be more specific such as that the main frame cannot be found. 
     If the main frame is found (step  404 : Yes), the present system corrects geometric distortion based on the main frame and the zebra frame (step  412 ). Geometric distortion can occur when a user uses a camera lens, for example on a smartphone or tablet camera, or on a digital camera, to decode an image. Accounting for distortion is described in further detail later, in connection with  FIG. 6 . 
     The present system locates the color calibration cells (step  408 ). As described earlier in connection with  FIGS. 2A-2B , in some embodiments, the color calibration cells are located inside the black frame and the white frame, on the left of the rectangular cells encoding the machine data. In other embodiments, the color frame could be located outside the black frame, between the black and white frames, or in other locations within the white frame. 
     Based on the color frame, the present system decodes the colors in the rectangular cells (step  410 ). In general, for every pixel found in the encoded image, the present system finds the closest sample pixel based on the color calibration cells and substitutes the sample pixel for the detected pixel. In some embodiments, the present system obtains a color-value correspondence. The present system determines cell size calibration based on the zebra frame. The present system divides the data image into color cells. When decoding the image, the present system captures or collects all colors belonging to a given pixel rectangle. If most of the pixel colors in the pixel rectangle could be recognized as one color from the color calibration cells, that color from the color calibration cells is used. Otherwise, the present system marks the pixel as an erasure. If a pixel-level block cannot be decoded, the present system treats the whole pixel block as an erasure. The present system reads the rectangular cells sequentially and determines an index of the nearest color from the color calibration cells to the median cell color. In particular, the present system determines the nearest color according to nearest Euclidean distance in the appropriate color space, according to Equation (1), described earlier. 
     The present system decodes the bytes (step  414 ). In some embodiments, the present system applies a corresponding decoder to the error-correcting encoder described earlier. For example, the present system applies a low-level Reed-Solomon decoder to the code stream obtained from the decoded colors. Accordingly, due to the nature of the error-correcting code, the present system is able to restore erasures and errors in the code stream. If the present system detects unrepairable blocks, the unrepairable blocks are marked as “erasures.” 
     The present system then descrambles the bytes (step  416 ). In some embodiments, the present system de-interleaves the resulting byte stream. 
     The present system then decodes the original information based on the decoded byte stream (step  418 ). In general, the present system uses a corresponding decoder to the error-correcting encoder described earlier, to restore pixel-block-level erasures and errors. In some embodiments, the present system applies a high-level Reed-Solomon decoder. After applying the high-level Reed-Solomon decoder, if some pixel blocks remain un-repairable, the present system attempts to change the indices to those indices corresponding to the next nearest color in the color calibration cells, and then repeats Reed-Solomon decoding of the modified block. If error free data is obtained, the present system maps the resulting sequence of integers to a bit stream. The present system then parses the resulting bit stream and computes a cyclic redundancy check (CRC) of the data. The present system compares the resulting CRC with the CRC contained in the header of the image. The present system then saves or appends the file. Two-level COLOR error correction schema with erasures and statistical color restoration 
     The two-level error correction used in the present system and described earlier in connection with  FIGS. 3 and 4  allows the present system to correct two types of errors: errors and erasures. In some embodiments, the Reed-Solomon error-correction encoding used is able to detect errors (which correspond to wrong, incorrect, or unexpected information) and erasures (which correspond to absent or missing information). 
     In some embodiments, correcting erasures can be performed twice as effectively than correcting errors. To make use of this feature, the present system uses a two-level error correction schema. 
     For example, assume N c =16 (i.e., 2 4 ). Accordingly, there are sixteen distinctive colors which allow an encoded image to encode 4 bits of information per rectangular cell. Every byte of information (8 bits) is encoded by two color indices. The error correction scheme has two levels. First, the byte array is divided into chunks, and every chunk is appended with Reed-Solomon source control data. Second, every byte is divided into two half-bytes (4 bits). The half-bytes are then gathered into groups or chunks which are appended with Reed-Solomon source control data. For example, the present system can process &lt;N c −1 half-bytes. That is, if N c =16, the present system gathers less than fifteen half-bytes. The group of half-bytes is then appended with Reed-Solomon source control data determined based on the group of half-bytes. Because the Reed-Solomon source control data can be about the same size as the input data, the addition of the Reed-Solomon source control data results in the size of the group reaching fifteen bytes. For example, the size of the input data and the control data block size can be fifteen bytes. Each half-byte in the group is mapped to an appropriate color, for example by using the corresponding half-bytes as indices into the color array. Accordingly, the encoding process applies two levels of Reed-Solomon encoding, first at the byte array level and second at the half-byte level. 
     As described earlier, when decoding the image, the present system collects all colors belonging to a detected pixel rectangle. If most of the colors in the pixel rectangle could be recognized as one of the colors in the color calibration cells, the present system uses the corresponding color in the color calibration cells. Otherwise, the pixel rectangle is marked as an erasure. If a pixel-level block cannot be decoded, the whole pixel block is treated as an erasure. As described earlier, the erasures can be further restored by an appropriate error-correction algorithm. The two-level error correction and leveraging of erasure determinations significantly improves the quality of the decoding described earlier in connection with  FIG. 4 . In particular, the two-level error correction described herein allows the present system to recover information which otherwise would be lost. 
     Restoration of Proper Color in the Case of Distinguishable Color Samples 
       FIG. 5  illustrates a block diagram of color calibration cells for restoration of proper color based on distinguishable color samples in accordance with certain embodiments of the present disclosure.  FIG. 5  includes color calibration cells  210 . 
     Color calibration cells  210  include all colors used to encode the rectangular cells. In some embodiments, a white frame or border surrounds color calibration cells  210  for the color white. In other embodiments, the present system may also include white as a color block in the color calibration cells arranged on the left hand side. The present system discerns each color based on its placement within color calibration cells  210 . The present system then stores distorted pixels as color samples. Different variants of a distorted pixel are saved to point or refer to the same correct pixel. That is, distorted pixels are determined dynamically, based on the position of their colors among the color calibration cells. The distorted pixels are assigned estimated colors according to the color calibration cells. 
     As described earlier, during decoding (shown in  FIG. 4 ), the present system translates a distorted pixel into one of the original colors in color calibration cells  210  using the nearest original color to the distorted pixel. For example, let color C=(R, G, B) represent a red green blue (RGB) component representation of the color. According to Equation (1), described earlier, a pseudo-Euclidean distance between two colors C 1  and C 2  can be given by ΔC, as described in Equation (1): 
     
       
         
           
             
               Δ 
               ⁢ 
               
                   
               
               ⁢ 
               C 
             
             = 
             
               
                 
                   
                     ( 
                     
                       2 
                       + 
                       
                         
                           r 
                           _ 
                         
                         256 
                       
                     
                     ) 
                   
                   ⁢ 
                   Δ 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   
                     R 
                     2 
                   
                 
                 + 
                 
                   4 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   Δ 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   
                     G 
                     2 
                   
                 
                 + 
                 
                   
                     ( 
                     
                       2 
                       + 
                       
                         
                           255 
                           - 
                           
                             r 
                             _ 
                           
                         
                         256 
                       
                     
                     ) 
                   
                   ⁢ 
                   Δ 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   
                     B 
                     2 
                   
                 
               
             
           
         
       
     
     This distance generates a native pseudo-Euclidean metric in the color space. A color mapping can be represented by the set of pairs: (distorted color)→(correct color). The distorted color can be C 1 , and the correct color can be C 2 . The number of such color pairs should be greater than or equal to N c , the total number of colors. This mapping can be determined based on the color calibration cells and on the color arrangement therein. 
     To restore a correct or proper color c* from a distorted color, the present system iterates over all pairs of distorted colors and correct colors. In particular, the present system selects the pair in which the distorted color portion of the pair is closest to the correct or proper color c*. In some embodiments, the determination of whether the distorted color portion is closest to the correct or proper color is made according to the pseudo-Euclidian metrics in the RGB color space. That is, the present system selects the pair in which ΔC is smallest according to Equation (1). The selected pair provides the correct color. Accordingly, the present system allows the correct colors to be restored, because the present system saves the correspondence between the distorted values and the original values. Therefore, the present system is able to leverage information about the way in which the colors were distorted relative to the original values as captured in the color calibration cells. 
     Frame Arrangement for Automatic Image Geometrical Distortion Correction 
       FIG. 6  illustrates a block diagram of a frame arrangement for geometrical distortion correction of an encoded image in accordance with certain embodiments of the present disclosure. 
     In some embodiments, the present system includes arrangements to recognize placement of rectangular cells and other elements in the encoded image. For example, these arrangements can include black frame  204 , white frame  206 , zebra frame  208 , and color calibration sidebar  210  (shown in  FIG. 2 ). The black frame and white frame surround the encoded rectangular cells. The color calibration sidebar contains sample colors (described earlier, in connection with  FIG. 5 ). The zebra frame surrounds the encoded rectangular cells to allow the present system to determine appropriate resolution and pixel division of the encoded image. 
     The black frame and white frame allow the present system to determine and correct nonlinear distortion. As described earlier, nonlinear distortion can be introduced, for example, by camera lenses when registering an encoded image for decoding. In some embodiments, the present system uses the white frame as follows. The white frame can be restricted by curve x left (y)  602 , curve x right (y)  604 , curve y top (x)  606 , and curve y bottom (x)  608 . For every point (x*,y*)  610  which belongs to the area restricted by curves  602 - 608 , the present system can determine parameters a and b (0≦a≦1 and 0≦b≦1) according to the following equations:
 
 x   left ( y *)+ a x   right ( y *)= x*   (1-a)
 
 y   top ( x *)+ b y   bottom ( x *)= y*   (1-b)
 
The equation described above maps the area restricted by curves  602 - 608  to a unit rectangle defined by 0≦a≦1, 0≦b≦1. The unit rectangle can represent what the image would look like when “straightened out,” by mapping the area restricted by curves  602 - 608  to the unit rectangle. That is, the distorted boundary of the image determined according to the area restricted by curves  602 - 608  can be mapped to the “straightened out” unit rectangle. The zebra frame can be used to determine parameters a and b. The present distortion correction therefore allows the original area having curved or non-linear sub-regions to be transformed according to the unit rectangle using parameters a and b.
 
     The zebra frame allows the present system to determine a resolution of the embedded picture, and to divide the image into “bold” or unknown pixels. As described earlier, the color value of some pixels may be unknown. “Bold” pixels allow the present system to determine the proper color value of a pixel according to a voting process. In some embodiments, the voting process can choose the color value of the most frequent pixel close to the “bold” or unknown pixel to be the color value of the “bold” pixel. Otherwise, if the result of the voting is unclear—for example, if there is no pixel with a frequency much larger than the other pixels—the present system can mark the pixel as an erasure (i.e., missing). Therefore, using the two-level error correction described earlier, the pixel can be restored. 
     Image Fragmentation 
       FIG. 7  illustrates a block diagram for frame fragmentation for distortion correction in accordance with certain embodiments of the present disclosure. The rectangular cells can be divided into sub-images  704  using separating lines  702 . 
     Frame fragmentation or image fragmentation refers to a complementary technique to distortion correction (shown in  FIG. 6 ). In some embodiments, dividing the image into a set of sub-images  704  allows the present system to work with every sub-image  704 , without requiring the distortion compensation technique described earlier because sub-images  704  are sufficiently small that there is not as much distortion as with the entire encoded image. In some embodiments, sub-images  704  can be separated with separating lines  702 . In some embodiments, separating lines  702  can be black lines, which can also became part of the zebra border. 
     The present system can use the same encoding and decoding techniques described earlier (shown in  FIGS. 3 and 4 ) for encoding and decoding of sub-images  704 . For example, the present system can leverage the two-level error correction, scrambler, etc. described earlier. 
     In some embodiments, the present system can skip the distortion correction described earlier (shown in  FIG. 6 ). The present system can leverage the relatively smaller size of sub-images  704  to skip non-linear distortion compensation of each sub-image  704 . Accordingly, the present system can decode sub-images  704  with better accuracy. 
     “Image” Based Data Exchange Between Devices without Using Wi-Fi or Cellular 
       FIG. 8  illustrates a block diagram of image based information exchange from one device to another device in accordance with certain aspects of the present disclosure.  FIG. 8  includes smartphones  802   a - b , and encoded images  804   a - b . Some smartphones currently have large displays and many are evolving to include even larger displays. These displays can be used for information exchange, for example using color-space encoded images  804   a - b . The color-space encoded images  804   a - b  can be encoded according to the encoding process described earlier, in  FIG. 3 . Accordingly, smartphones  802   a - b  are able to exchange information using the encoded images. For example, an embedded camera on smartphone  802   b  can register or capture an encoded image  804   a  being displayed on smartphone  802   a.    
     Embedded cameras used on devices such as smartphones  802   a - b  are improving. As described herein, the resolution per frame as captured by embedded cameras can be less important, because the requirements on the number of pixels which can be pixel number limitation can be avoided. Descriptions of the pixel number limitation are described in further detail below. 
     In some embodiments, smartphones  802   a - b  can have hardware modules or software applications loaded thereon, for example for encoding or decoding according to the processes described in  FIGS. 3 and 4 . A first user can create machine data or otherwise store machine data on a device such as a smartphone. The first user can then decide to exchange related information between devices, for example with a second user. The machine data created by the first user or stored on the phone can be encoded according to the process described in  FIG. 3 , and then displayed on the smartphone display for exchanging information with smartphone  802   b.    
     As described earlier, smartphone  802   b  can acquire the encoded image through its embedded camera. Advantageously, this acquisition does not require smartphone  802   b  to download or acquire encoded image  804   a  through electromagnetic radio transmissions such as a wireless or cellular network. Smartphone  802   b  can perform the decoding as described in  FIG. 4  to determine the machine data from the first user. As described earlier, the decoding can be performed in hardware or in software installed on smartphone  802   b . The machine data encoded by the first user can be displayed on the screen or otherwise stored in smartphone  802   b.    
     In some embodiments, security can be added to the encoded image. For example, when the present system compresses or archives the machine data, the present system can add a password or otherwise encrypt the relevant machine data. 
     In some embodiments, if there are low light conditions and/or low camera resolution for smartphone  802   b  to register or otherwise capture encoded image  804   a , smartphone  802   a  can partition or divide the information to be transmitted. For example, smartphone  802   a  can transmit a first frame including only partial information. In some instances, the first frame can include the color calibration frame for smartphone  802   b  to calibrate colors in preparation for decoding encoded image  804   a , as described earlier in connection with  FIG. 5 . In some embodiments, the first frame can include the main frames (i.e., the black frame and/or the white frame) to correct geometrical distortions, etc., as described earlier in connection with  FIG. 6 . Generally, smartphone  802   a  can construct and generate special frames for partial transmission. The special frames can include the color calibration frame, the main frames, or the zebra frame, to obtain a stable information and data exchange. 
     In some embodiments, smartphones  802   a - b  can be placed substantially against each other, for example by aligning the embedded camera of smartphone  802   b  with the display of smartphone  802   a  displaying encoded image  804   a . Accordingly, smartphones  802   a - b  can sense the proximity to establish automatically the data transmission channel described earlier. In further embodiments, smartphones  802   a - b  can change the position of which smartphone represents the source for sending machine data, and which smartphone represents the sink for receiving machine data. 
     Direct Data Exchange 
       FIG. 9  illustrates a block diagram of an example of information exchange of a color space encoded image in accordance with certain embodiments of the present disclosure.  FIG. 9  includes a number of devices including smartphones  906   a ,  912   a , camera  906   b ,  912   b , palmtop or handheld device  906   c ,  912   c , and tablet or e-reader  906   d ,  912   d . In some embodiments, the present system can include information exchange between a number of devices which can register, capture, or “see” an encoded image  102  on a display  902 . The devices which can register encoded image  102  include devices with embedded cameras  904 . For example, the devices can include smartphone  912   a , camera  912   b , palmtop or handheld device  912   c , and tablet or e-reader  912   d . In some embodiments, these devices can be similar to devices  106   c - f  (shown in  FIG. 1 ). These registering devices can register or capture the corresponding data source. In some embodiments, the information exchange described herein can include data distribution including multiple devices. Accordingly, the information exchange described herein can include point-to-multipoint data distribution, in which a number of devices all capture a single encoded image  102 . 
     In some embodiments, the present system can include sequential frame transmission of multiple encoded images. The encoded images can include multiple video frames, such as video frames  910   a - c . Accordingly, the present system allows exchange of video files such as machine data including movies or films  908 . 
     In some embodiments, the sequential frame transmission described herein can be used for machine data other than video files. For example, multiple encoded images can be used to encode large files and/or large amounts of information. Smartphones such as smartphones  906   a ,  912   a  are capable of recording full high definition (HD) video. HD video can include video at 1920×1080 pixels, and at least 25 frames per second (fps). Accordingly, smartphones  912   a  can often include high-performance cameras such as for capturing photographs or video. Furthermore, smartphone displays continue to improve, allowing for even more resolution for encoding machine data, and for displaying and transmitting encoded images. 
     Smartphones often include a second camera, for example on the front of the smartphone along with the display, for use in videoconferencing. In some embodiments, the present system can allow two devices to be placed with their displays next to or adjacent with each other. In such an orientation, embodiments of the present disclosure can use the front camera. Advantageously, having devices paired as described herein can allow the devices to exchange information interactively. For example, a first device, such as tablet  906   d  can display a first frame. As described earlier, the first frame can include color calibration information. When the second device has completed processing the color calibration information, the second device can encode an acknowledgement in an encoded image of its own (not shown), and send the acknowledgement for the first device to decode. In some embodiments, the second device can send a request for the next frame or additional partial information. 
     In further embodiments, the present system can send a number of encoded images, for example in a video-like transmission. This video-like transmission can be used for two-way interactive or one-way directional information or data exchange. 
       FIG. 10  illustrates information exchange using a photo camera to display a color space encoded image in accordance with certain embodiments of the present invention.  FIG. 10  illustrates a photo camera  1002  and a smartphone  802   b . Photo camera  1002  can display an encoded image  804   a . Current digital cameras such as photo camera  1002  have good optics in their camera lenses. Current digital cameras often have good displays as well, which can be used for displaying encoded image  804   a.    
     Camera manufacturers are also adding wireless connectivity such as Wi-Fi or cellular connectivity, or even GPS receivers to make cameras “connected.” Cameras can also include digital signal processors used for image data processing. 
     In some embodiments, the present system includes digital signal processors modified in photo camera such as photo camera  1002 . The modifications can include hardware modules or embedded software such as firmware for encoding or decoding color space images in accordance with the processes described in  FIGS. 3 and 4 . 
     Accordingly, photo cameras can be modified for information or data exchange between cameras. A camera is a good “image” acquisition, registration, or capture device, due to high quality optics and ability to work under difficult light conditions. Information acquired by a camera can often be stored on a memory card, for example flash memory. As described earlier, the present system can allow a user to insert a memory card into a compatible device, such as a PC or notebook computer. Modules on the PC or notebook computer can decode a color space encoded image without requiring radio-related approaches such as using a Wi-Fi or cellular network. 
     In some embodiments, an embedded camera on a PC or tablet can be used as an image acquisition, registration, or capture device. In further embodiments, the present system can use the display on the PC or tablet as a data source device as well, for example to display encoded image  804 . Accordingly, the decoding modules described earlier can be utilized on corresponding decoding devices. 
     Although specific steps are disclosed in  FIGS. 3 and 4 , such steps are exemplary. That is, the present system is well-suited to performing various other steps or variations of the steps recited in  FIGS. 3 and 4 . The steps in  FIGS. 3 and 4  may be performed in an order different than presented, and that not all of the steps may be performed.  FIGS. 3 and 4  include processes that, in various embodiments, are carried out by a processor under the control of computer-readable and computer-executable instructions. Embodiments of the present disclosure may thus be stored as non-transitory computer-readable media or computer-executable instructions including, but not limited to, firmware updates, software update packages, or hardware (e.g., ROM). 
     Reference has been made in detail to various embodiments in accordance with the the present disclosure, examples of which are illustrated in the accompanying drawings. While the invention has been described in conjunction with various embodiments, these various embodiments are not intended to limit the invention. On the contrary, the invention is intended to cover alternatives, modifications, and equivalents, which may be included within the scope of the invention as construed according to the appended claims. Furthermore, in the detailed description of various embodiments, numerous specific details have been set forth in order to provide a thorough understanding of the invention. However, the invention may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuits have not been described in detail, so as not to unnecessarily obscure aspects of the invention. 
     Some portions of the detailed descriptions have been presented in terms of procedures, logic blocks, processing, and other symbolic representations of operations on data bits within a non-transitory computer memory. These descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. In the present disclosure, a procedure, logic block, process, or the like, is conceived to be a self-consistent sequence of operations or steps or instructions leading to a desired result. The operations or steps are those utilizing physical manipulations and transformations of physical quantities. Usually, although not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated in a computer system or computing device. It has been convenient at times, principally for reasons of common usage, to refer to these signals as records, transactions, bits, values, elements, symbols, characters, samples, pixels, or the like. 
     All of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the foregoing discussions, it is appreciated that throughout the present disclosure, discussions utilizing terms such as “deactivating,” “disabling,” “re-activating,” “enabling,” “sending,” “receiving,” “determining,” “flushing,” “responding,” “generating,” “making,” “blocking,” “accessing,” “taking a snapshot,” “associating,” “allowing,” “updating,” or the like, refer to actions and processes of a computer system or similar electronic computing device or processor. The computer system or similar electronic computing device manipulates and transforms data represented as physical (electronic) quantities within the system memories, registers or other such information storage, transmission or display devices. 
     The present systems and methods can be implemented in a variety of architectures and configurations. For example, the present systems and methods can be implemented as part of a distributed computing environment, a cloud computing environment, a client server environment, etc. The embodiments described herein may be discussed in the general context of computer-executable instructions residing on some form of non-transitory computer-readable storage medium, such as program modules, executed by one or more computers, computing devices, or other devices. As described earlier, non-limiting examples of computer-readable storage media may include storage media and communication media. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or distributed as desired in various embodiments. 
     The foregoing descriptions of specific embodiments of the present systems and methods have been presented for purposes of illustration and description. The specific embodiments are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and many modifications and variations are possible in light of the above description. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.