Patent Publication Number: US-2009231461-A1

Title: Image capture device providing color adjustment and color adjustment method thereof

Description:
BACKGROUND 
     1. Field of the Invention 
     The present invention relates to image capture and, particularly, to an image capture device providing color adjustment and a color adjustment method thereof. 
     2. Description of Related Art 
     Color adjustment involves changing a color in an image or a portion of an image. This adjustment is conventionally accomplished in post-processing with a computer, which can be difficult and inconvenient. 
     Therefore, it is desirable to provide an image capture device and a color adjustment method, which can overcome the described limitations. 
     SUMMARY 
     In an embodiment, a digital still camera (DSC) includes an encoder, a display panel, and a color adjustment unit. The encoder is configured to encode an image signal in the DSC into a first preview image. The display panel is configured to display the first preview image so that a user may judge if color adjustment is desired. The color adjustment unit is configured to adjust the color of the image signal in response to user input after the first preview image is displayed. The adjusted image signal is then encoded by the encoder as a second preview image displayed in real time by the display panel so that the user may judge if further color adjustment is needed or if the adjusted image may be accepted as a final image and stored. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the present image capture device and color adjustment method will be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present image capture device and color adjustment method. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is a functional diagram of a digital still camera (DSC) including a display panel, according to a first exemplary embodiment. 
         FIG. 2  is a schematic view of the display panel of  FIG. 1 . 
         FIG. 3  is a flowchart of a color adjustment method, according to a second exemplary embodiment. 
         FIG. 4  is a flowchart of a color adjustment method, according to a third exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present image capture device and color adjustment method will now be described in detail with reference to the drawings. while, in the following described embodiments, the image capture device is a digital still camera (DSC), it should be understood that the image capture device is not limited by these embodiments and can be any other electronic device providing image capture capability such as a mobile phone with a camera module. 
     Referring to  FIG. 1 , a DSC  10 , according to an exemplary embodiment, includes an encoder  12 , a display panel  14 , and a color adjustment unit  16 . The encoder  12 , such as a video encoder, is configured to encode an image signal currently generated by or stored in the DSC  10  (see following) into a first preview image, which may comprise a video signal (i.e., putting several images together as a video signal, or repeating a same image as a video signal). The display panel  14 , such as a liquid crystal display (LCD) panel, is configured to display the first preview image. The color adjustment unit  16  is configured to adjust the color of the image signal in response to user input after the first preview image is displayed. The adjusted image signal is also encoded by the encoder  12  as a second preview image and can undergo further color adjustment or be accepted and stored. 
     In particular, the color adjustment unit  16  may adjust the color of the image signal by changing color values of pixels of the image signal in a specific color space (e.g., RGB, or YUV space, wherein Y represents luminance component, U, V represent two chrominance components, see following). 
     Typically, the DSC  10  further includes a lens unit  18 , an image sensor  20 , a timing generator (TG)  22 , a digital signal processor (DSP)  24 , a JPEG CODEC  26 , an input unit  28 , a memory unit  30 , and a micro central unit (MCU)  32 . 
     The lens unit  18  is configured to transmit an optical image to the image sensor  20 , such as a charge coupled device (CCD). The image sensor  20  is configured to convert the optical image into an image signal. The TG  22  is configured to drive the image sensor  20  to repeat output of the image signal at a predetermined rate (e.g., 1/30s) as consecutive image frames. 
     Understandably, the lens unit  18  may include a zoom lens  34 , focus lens  36 , and a mechanical shutter  38  to enable the lens unit  18  to zoom and/or focus the optical image on the image sensor  20  and regulate exposure time of the image sensor  20 . It should be noted that if the image sensor  20  is a CCD image sensor, an analog-to-digital converter (ADC, not shown) should be included in the image sensor  20  so that the image frames can be processed by the DSP  24 . It also should be understood that the image sensor  20  bears a color filter of Bayer pattern such that the image frames may include three color components such as red (R), green (G), and blue (B) (RAW file). That is, the image frames may be represented in an RGB space. 
     The DSP  24  is configured for processing the image frames and may include an optical black clamping unit, a lens distortion compensation unit, a white balance unit, a gamma correction unit, a color interpolation unit (not shown), and a color space converter (CSC)  40  for applying various corresponding processing to the image frames. The CSC  40  is configured to convert the color space of the image signal RGB into YUV. That is, after color space conversion, the image frames may be also represented by color components YUV. 
     The JPEG CODEC  26  is configured to convert a current image frame of an image signal to a JPEG file. The memory unit  30  is configured to store the compressed JPEG file. The input unit  28  is configured to receive various user input instructing the MCU  32  to control and coordinate the various involved components of the DSC  10 . For example, the input unit  28  may include a shutter  42  and color adjustment control (CAC)  44 . The shutter key  42  is configured to activate the JPEG CODEC  26  to compress a current image frame or a current adjusted image frame when fully depressed as a JPEG file. The CAC  44  is configured to receive color adjustment parameters such as the color (component) needed to be changed or the amount of change, and thereby instructs the MCU  32  to control the color adjustment unit  16  based on the received color adjustment parameters. 
     In this embodiment, the CAC  44  is incorporated into the display panel  14 , as a touch screen. As shown in  FIG. 2 , a number of representations such as colors A˜J and brightness levels 0˜9 are shown in corresponding sensor locations  46  defined in the screen  48  of the display panel  14  when the image signal is displayed thereon. A number of sensors  50  are employed and attached to the display panel  14  under the sensor locations  46 . The sensors  50  are configured to identify which sensor location  46  is contacted and coupled to the MCU  32  to provide response to the contact. As shown, in this embodiment, the image signal can be adjusted among colors A˜J (in RGB space) and brightness levels 0˜9 (in YUV space). It should be noted that the CAC  44  is not limited by this embodiment but can be designed depending on need. 
     One method of color adjustment can be performed before a JPEG file of the image signal is created, according to the following steps  102 - 114 . 
     In Step  102  a number of image frames of an image signal are captured that include a current image frame by the image sensor  20  and the lens unit  18 . 
     In Step  104 , the current image frame is encoded as a first preview image. Encoder  12  encodes the image frames of the image signal as a video signal shown on the display panel  14  so that the user may judge what, if any, color adjustment is desired, with parameters adjusted via the CAC  44 . 
     In Step  106 , the first preview image is displayed on the display panel. 
     In Step  108 , the color of the current image frame is adjusted after the first preview image is displayed. Color adjustment unit  16  receives a current image frame and the color adjustment parameters and adjusts the color of the current image frame based thereon. 
     In Step  110 , the adjusted current image frame is encoded as a second preview image by the encoder  12 . 
     In Step  112 , the second preview image is displayed to allow determination of the need for further color adjustment by the display panel  14 . 
     In Step  114 , the adjusted current image frame is stored if deemed complete, by depression of shutter key  42 , at which time the adjusted image frame is sent to the JPEG CODEC  26 , which compresses the adjusted image frame as a JPEG file, which is then sequentially stored in the memory unit  30 . 
     If the adjusted current image frame is not deemed complete, the process returns to step  108  for more color adjustment until completion is achieved. 
     Additionally, the DSC  10  can further adjust the color of an existing JPEG file, by the following steps. 
     In Step  202 , an image signal stored in the image capture device is selected, using display panel  14  to browse stored images. 
     In Step  204 , the selected image signal is encoded as a first preview image. 
     In Step  206 , the first preview image is displayed to allow determination of the need for color adjustment. The encoder  12  encodes the chosen JPEG file as a first preview image that shown on the display panel  14 . 
     In Step  208 , if deemed necessary, the color of the selected image is adjusted after the first preview image is displayed, setting color adjustment parameters via the CAC  44  based on the first preview image. The color adjustment unit  16  receives the JPEG file and the color adjustment parameters and adjusts the color of the JPEG file accordingly. 
     In Step  210 , the adjusted image signal is encoded as a second preview image. 
     In Step  212 , the second preview image is displayed to allow determination of whether further color adjustment is needed or if the adjusted image is acceptable; and 
     In Step  214 , if deemed acceptable, the adjusted JPEG file is stored, replacing the original JPEG file. If not, more color adjustment can be performed until acceptability is achieved. 
     It will be understood that the above particular embodiments and methods are shown and described by way of illustration only. The principles and the features of the present invention may be employed in various and numerous embodiment thereof without departing from the scope of the invention as claimed. The above-described embodiments illustrate the scope of the invention but do not restrict the scope of the invention.