JP2018050322A - Image processing apparatus, image processing method, program, and imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically determine at least one extraction color region by using color information on an input image signal and perform image processing.SOLUTION: An extraction color region including at least a partial region in an image is determined by using color information on an input image signal (captured image signal, reproduction image signal, etc.). Then, image processing is performed on the extraction color region and/or the remaining region except the extraction color region to obtain an output image signal. For example, by performing achromatization processing on the remaining region of the input image signal except the extraction color region, so-called partial color effect can be reliably realized.SELECTED DRAWING: Figure 1

Description

  The present technology relates to an image processing device, an image processing method, a program, and an imaging device. In particular, the present technology relates to an image processing apparatus or the like that performs image processing by extracting at least one color region from color regions included in an input image signal.

  Conventionally, it is known that an input image signal is subjected to different processes in a specific area in the image and other areas in the image to obtain an output image signal. For example, it is known to realize a so-called partial color effect by setting an area other than the color area specified by the user as an achromatic color. Further, for example, Patent Document 1 describes that only a main subject in focus is two-dimensionally specified and displayed in color within an imaging screen.

Japanese Patent Laid-Open No. 06-098232

  Conventionally, it is not known that image processing is performed by automatically determining at least one extraction color region using color information of an input image signal.

  An object of the present technology is to perform image processing by automatically determining at least one extraction color region using color information of an input image signal.

The concept of this technology is
An extraction color region determination unit that performs processing for determining an extraction color region including at least a partial region in the image using color information of the input image signal;
An image processing unit that performs image processing on the extracted color region determined by the extracted color region determining unit and / or other regions other than the extracted color region of the input image signal to obtain an output image signal; Provided in an image processing apparatus.

  In the present technology, the extracted color region determination unit performs processing for determining an extracted color region including at least a partial region in the image using color information of the input image signal. For example, the extraction color area determination unit is configured to perform a process of determining the extraction color area in the second image area that is narrower than the first image area when the extraction color area cannot be determined in the first image area. Also good. By narrowing the image area in this way, it is possible to reliably determine the extracted color area.

  In this case, for example, the extracted color area determination unit performs a process of allocating to a plurality of color areas for each pixel or for each block including a predetermined number of pixels in the first image area, and then the frequency is set to the threshold value. When there is a color area that exceeds, at least one of the color areas is determined as the extracted color area, and when there is no area whose frequency exceeds the threshold, the extracted color in the second image area that is narrower than the first image area A process for determining an area is performed.

  In this case, for example, in the extraction color region determination unit, the second image region is an image region in which the first image region is narrowed toward the center of the screen. In this case, for example, in the extraction color region determination unit, the second image region is an image region in which the first image region is narrowed toward the in-focus position in the screen. By narrowing toward the in-focus position in this way, it becomes possible to determine a color area more suitable for the user as an extracted color area.

  In addition, for example, the extracted color area determination unit performs a process of allocating to a plurality of color areas for each pixel or for each block including a predetermined number of pixels in the predetermined image area, and extracts the above based on the frequency of each color area A region may be determined. In this case, when there are a plurality of color areas whose frequency exceeds the threshold, the extracted color area determining unit determines a predetermined number of color areas as the extracted color area from the higher frequency.

  In this case, the extracted color area determination unit may prompt the user to select an extracted color area when there are a plurality of color areas whose frequency exceeds the threshold. In this case, the top N regions (N is an integer of 2 or more) having a high frequency among the plurality of color regions whose frequencies exceed the threshold are displayed on the display unit as candidate color regions, and based on the display on the display unit, A user selection acquisition unit that prompts the user to select an extraction color region may be further provided. In this case, it is possible to determine a color area suitable for the user as the extracted color area.

  Note that the display unit that displays the candidate color region does not need to exist in the image processing apparatus, and may be an external device. In addition, the user operation unit for the user to select the extraction color area does not need to exist in the image processing apparatus, and may be an external device such as a remote controller or via a network.

  The image processing unit performs image processing on the extracted color region determined by the extracted color region determining unit and / or other regions other than the extracted color region of the input image signal to obtain an output image signal. . For example, a process of enhancing the saturation is performed on the extracted color area of the input image signal, and a process of making an achromatic color on the other areas excluding the extracted color area of the input image signal is performed.

  As described above, in the present technology, it is possible to perform image processing by automatically determining at least one extraction color region using the color information of the input image signal. Therefore, for example, the partial color effect can be reliably realized.

  In the present technology, for example, the extracted color region determination unit may update the determined extracted color region when the imaging condition of the input image signal changes. As a result, it is possible to prevent the extracted color region from changing carelessly.

  According to the present technology, it is possible to perform image processing by automatically determining at least one extraction color region using color information of an input image signal.

It is a block diagram showing an example of composition of an image processing device as a 1st embodiment of this art. It is a flowchart which shows the process sequence of the image analysis part which comprises an image processing apparatus. It is a figure for demonstrating an example (example narrowing toward a screen center) of how to narrow a color information analysis area. It is a figure for demonstrating the other example (example narrowing toward the focus position in a screen) how to narrow a color information analysis area | region. It is a figure which shows the example of a classification | category of the color area in a distribution process. It is a figure which shows the example of a distribution process result (example in which all of the frequency of color area | region A-G are less than a threshold value). It is a figure which shows the example of a sorting process result (example in which the frequency of the color area E exceeds the threshold value among the frequencies of the color areas A to G, and the frequency of the other color areas is less than the threshold value). It is a figure which shows the example of a sorting process result (example in which the frequency of color area B, D, F exceeds a threshold among the frequencies of color areas A-G, and the frequency of other color areas is less than a threshold). It is a block diagram showing an example of composition of a digital still camera (imaging device) as a 2nd embodiment of this art. It is a flowchart which shows the process sequence of the image-analysis part which comprises a digital still camera. It is a figure which shows the example of a display of the candidate color area | region in the display part of a digital still camera.

Hereinafter, modes for carrying out the invention (hereinafter referred to as “embodiments”) will be described. The description will be given in the following order.
1. 1. First embodiment 2. Second embodiment Modified example

<1. First Embodiment>
[Configuration example of image processing apparatus]
FIG. 1 shows a configuration example of an image processing apparatus 100 as the first embodiment of the present technology. The image processing apparatus 100 includes an image analysis unit 101 and an image processing unit 102. The image analysis unit 101 constitutes an extraction color region determination unit.

  The image analysis unit 101 uses the color information of the input image signal SVin to perform processing for determining an extracted color region including at least a partial region in the image. Here, the input image signal SVin is a color image signal, and includes, for example, a luminance signal Y, a red color difference signal Cr, and a blue color difference signal Cb. The input image signal SVin is, for example, a captured image signal obtained by the imaging unit or a reproduced image signal obtained by temporarily recording the captured image signal on a recording medium and then reproducing the image from the recording medium.

  When the extracted color area cannot be determined in the first image area, the image analysis unit 101 performs a process of determining the extracted color area in the second image area that is narrower than the first image area. In this case, the image analysis unit 101 performs a process of allocating to one of a plurality of color regions for each pixel or for each block including a predetermined number of pixels in the first image region. Thereafter, when there is a color region whose frequency exceeds the threshold, the image analysis unit 101 determines at least one color region as an extracted color region.

  On the other hand, when there is no region whose frequency exceeds the threshold, the image analysis unit 101 performs a process of determining the extraction region in the second image region that is narrower than the first image region. That is, the image analysis unit 101 performs a process of allocating to any one of a plurality of color regions for each pixel or for each block including a predetermined number of pixels in the second image region. Thereafter, when there is a color region whose frequency exceeds the threshold, the image analysis unit 101 determines at least one color region as an extracted color region.

  Hereinafter, when there is no region whose frequency exceeds the threshold value, the image analysis unit 101 sets the second image region as the first image region, and determines the extraction color region in the second image region narrower than the first image region. Repeat the process to do.

  The flowchart of FIG. 2 shows the processing procedure of the image analysis unit 101. The image analysis unit 101 performs processing according to this flowchart for each frame or for each predetermined number of frames. In step ST1, the image analysis unit 101 starts processing, and then proceeds to processing in step ST2. In step ST2, the image analysis unit 101 sets a color information analysis region.

  The image analysis unit 101 initially sets the entire screen as a color information analysis region, and thereafter narrows the region every time the processing returns to step ST2. In this case, the color information analysis area before the change constitutes a first image area, and the color information analysis area after the change constitutes a second image area. FIG. 3 shows an example of how to narrow the color information analysis region. FIG. 3A shows an initial state in which the entire screen is set as a color information analysis area. In this example, as shown in FIG. 3B, the screen is narrowed toward the center of the screen.

  FIG. 4 shows another example of how to narrow the color information analysis region. FIG. 4A shows an initial state in which the entire screen is set as a color information analysis area. In this example, as shown in FIG. 4B, the image is narrowed toward the in-focus position in the screen. In this case, the image analysis unit 101 acquires information on the in-focus position together with the input image signal SVin from the imaging unit or the reproduction unit. Although detailed description is omitted in the imaging unit of the digital still camera (imaging device), it is possible to focus on a subject existing at a predetermined position on the screen by, for example, a phase difference autofocus method.

  Although illustration is omitted, as another example of narrowing the color information analysis area, it is possible to narrow toward the detection position of a specific object such as a face. In this case, the image analysis unit 101 acquires information on the detection position of the specific object or from the reproduction unit together with the input image signal SVin.

  Returning to FIG. 2, the image analysis unit 101 performs color frequency distribution analysis in step ST3. That is, the image analysis unit 101 performs a process of assigning to one of a plurality of color regions for each pixel or for each block including a predetermined number of pixels, for example, 8 × 8 pixels. The image analysis unit 101 performs this distribution process based on color information for each pixel or block.

  Examples of the color information include hue information, saturation information, hue and saturation information, and information corresponding to hue. For example, a red color difference signal Cr and a blue color difference signal Cb are used as hue information. For example, B / G and R / G are used as information corresponding to hue. Here, B indicates a blue signal, R indicates a red signal, and G indicates a green signal.

  For example, the case where the above-described distribution process is performed based on hue information for each pixel or block will be further described. In this case, the hue is classified into a predetermined number of color regions in advance. For example, FIG. 5 shows a classification example classified into seven types of color regions, that is, color regions A to G. In this example, the color wheel is cut at the color region A and developed.

  The image analysis unit 101 uses the red color difference signal Cr and the blue color difference signal Cb for each pixel or each block to determine which of the color regions A to G belongs, and performs distribution. Note that the red color difference signal Cr and the blue color difference signal Cb in the block are the average value or intermediate value of the red color difference signal Cr and the blue color difference signal Cb in a predetermined number of pixels included in the block, respectively.

  6 to 8 each show an example of the distribution processing result. In these examples, the frequency of each color region is shown as a proportion of the screen. Here, the “screen” means the “color information analysis region” set in step ST2. The example of FIG. 6 is an example in which all the frequencies of the color regions A to G are less than the threshold value. The example of FIG. 7 is an example in which the frequency of the color region E exceeds the threshold value among the frequencies of the color regions A to G, and the frequency of the other color regions is less than the threshold value. Furthermore, the example of FIG. 8 is an example in which the frequency of the color regions B, D, and F exceeds the threshold value among the frequencies of the color regions A to G, and the frequency of the other color regions is less than the threshold value. The threshold is set to 30 to 40%, for example, but is not limited to this.

  Returning to FIG. 2, next, in step ST <b> 4, the image analysis unit 101 determines whether there is a color region whose frequency exceeds the threshold value. When determining that there is no color region whose frequency exceeds the threshold (see FIG. 6), the image analysis unit 101 returns to step ST2 and changes the color information analysis region. In this case, the color information analysis area (second image area) after the change is narrower than the color information analysis area (first image area) before the change (see FIGS. 3 and 4).

  On the other hand, when determining that there is a color region whose frequency exceeds the threshold (see FIGS. 7 and 8), the image analysis unit 101 proceeds to the process of step ST5. In step ST <b> 5, the image analysis unit 101 determines at least one color area as an extracted color area from among color areas whose frequency exceeds a threshold, and outputs information on the extracted color area on the screen.

  In this case, when there is only one color area whose frequency exceeds the threshold (see FIG. 7), the image analysis unit 101 determines the color area as an extracted color area. Further, in this case, when there are a plurality of color regions whose frequency exceeds the threshold (see FIG. 8), the image analysis unit 101, for example, one of the top color regions or a predetermined number of colors among the plurality of color regions The area is determined as the extracted color area.

  After step ST5, the image analysis unit 101 ends the process in step ST6.

  Returning to FIG. 1, the image processing unit 102 performs image processing on the input image signal SVin based on the extracted color region determined by the image analysis unit 101 to obtain an output image signal SVout. In this case, the image processing unit 102 performs image processing on the extracted color area and / or other areas excluding the extracted color area of the input image signal SVin. In other words, the image processing unit 102 performs image processing on at least one region of the input image signal SVin, that is, the extraction region and other regions other than the extraction region. Further, when image processing is performed on both regions, different image processing is performed on the extraction region and other regions other than the extraction region. The image processing unit 102 performs, for example, a process of enhancing saturation on the extracted color region of the input image signal SVin. Further, the image processing unit 102 performs, for example, an achromatic color, that is, a process of setting the saturation to zero, on the other areas excluding the extracted color area of the input image signal SVin.

  The operation of the image signal processing apparatus 100 shown in FIG. 1 will be described. An input image signal SVin, for example, a captured image signal or a reproduced image signal is supplied to the image analysis unit 101 and the image processing unit 102. In the image analysis unit 101, an extraction color region including at least a partial region in the image is determined using the color information of the input image signal SVin, and the region information is supplied to the image processing unit 102.

  Then, the image processing unit 102 performs image processing on the input image signal SVin based on the extracted color region determined by the image analysis unit 101 to obtain an output image signal SVout. In this case, the image processing unit 102 performs image processing on the extracted color region and / or other regions other than the extracted color region of the input image signal SVin. For example, the effect of a so-called partial color is realized by performing a neutral color processing on the other areas excluding the extracted color area of the input image signal SVin.

  As described above, in the image processing apparatus 100 shown in FIG. 1, the image analysis unit 101 automatically determines at least one extracted color region using the color information of the input image signal SVin. Therefore, the image processing unit 102 can reliably perform image processing based on the information of the extracted color area on the input image signal SVin. For example, the effect of so-called partial color can be reliably realized by performing the process of making the achromatic color other than the extracted color area of the input image signal SVin.

  In the image processing apparatus 100 shown in FIG. 1, when the extracted color region cannot be determined, the image analysis unit 101 changes the direction of narrowing the color information analysis region and performs the process of determining the extracted color region again. Therefore, at least one extracted color area can be automatically determined.

  Some common digital still cameras have a focus point for realizing autofocus, and others allow a user to freely set a focus position. In general, since a subject to be focused is a main subject, there is a high possibility that many color regions to be extracted are included. Therefore, by narrowing the color information analysis region toward the in-focus position (focus point), it is possible to determine a color region that suits the user's preference as the extracted color region.

  In the image processing procedure 100 shown in FIG. 1, the input image signal SVin includes the luminance signal Y, the red difference signal Cr, and the blue difference signal Cb. However, the input image signal SVin is a three primary color signal, that is, It may consist of a red signal R, a green signal G, and a blue signal B. In this case, the image analysis unit 101 and the image processing unit 102 may perform processing using the red signal R, the green signal G, and the blue signal B, and appropriately the luminance signal Y, the red difference signal Cr, and the blue difference signal. Processing may be performed after conversion to Cb.

<2. Second Embodiment>
[Configuration example of digital still camera]
FIG. 9 shows a configuration example of a digital still camera (imaging device) 100A as the second embodiment of the present technology. 9, parts corresponding to those in FIG. 1 are denoted by the same reference numerals or corresponding numerals, and detailed description thereof will be omitted as appropriate. The digital still camera 100 </ b> A includes a camera body 110, a CPU 111, a memory 112, a user operation unit 113, and a display unit 114, and these units are connected to each other via an internal bus 115.

  The CPU 111 controls the operation of each unit of the digital still camera 100A. The memory 112 is composed of a flash ROM, a DRAM, etc., although not shown. The flash ROM stores control software and data. The DRAM constitutes a work area for the CPU 111. The CPU 111 develops software and data read from the flash ROM on the DRAM and activates the software to control each unit of the digital still camera 100A.

  The user operation unit 113 and the display unit 114 constitute a user interface. The user operation unit 113 includes a key, a button, a dial, a touch panel disposed on the display surface of the display unit 114, or the like disposed on a housing (not shown) of the digital still camera 100A. The display unit 114 includes a display panel such as an LCD (Liquid Crystal Display).

  The camera body 110 includes an imaging unit 103, an image analysis unit 101A, an image processing unit 102, and an output unit 104. The imaging unit 103 captures a subject to obtain a captured image signal SVa, and outputs the captured image signal SVin. The captured image signal SVa is a color image signal, and includes, for example, a luminance signal Y, a red color difference signal Cr, and a blue color difference signal Cb.

  The imaging unit 103 includes an autofocus function such as a phase difference autofocus method, and can focus on a subject existing at a predetermined position on the screen. The imaging unit 103 has a function of detecting a specific object such as a face. In addition to outputting the above-described captured image signal SVa, the imaging unit 103 outputs additional information Iadd including in-focus position information, specific object detection position information, and the like.

  Similar to the image analysis unit 101 in the image processing apparatus 100 shown in FIG. 1, the image analysis unit 101A uses the color information of the captured image signal SVa to determine an extraction color region including at least a partial region in the image. I do. When the extraction color area cannot be determined in the first image area, the image analysis unit 101A performs a process of determining the extraction color area in the second image area that is narrower than the first image area.

  In this case, the image analysis unit 101A performs a process of allocating to one of a plurality of color regions for each pixel or for each block including a predetermined number of pixels in the first image region. Thereafter, when there is a color region whose frequency exceeds the threshold, the image analysis unit 101A determines at least one color region as the extracted color region. On the other hand, when there is no region whose frequency exceeds the threshold, the image analysis unit 101A performs a process of determining an extraction region in the second image region that is narrower than the first image region.

  Note that the image analysis unit 101A updates the extracted color region to be determined when there is a change in the imaging state. Here, the change in the imaging state means a change in the imaging state when the user explicitly changes the exposure mode or the zoom operation from the user operation unit 113. As a result, it is possible to avoid the extraction color region from changing one after another due to a small angle of view shift or the movement of the subject that is not intended by the user.

  The flowchart of FIG. 10 shows the processing procedure of the image analysis unit 101A. For example, based on a user start operation from the user operation unit 113, the image analysis unit 101A starts processing in step ST11, and then proceeds to processing in step ST12. In step ST12, the image analysis unit 101A sets a color information analysis region in the same manner as the process performed by the image analysis unit 101 of the image processing apparatus 100 in FIG. 1 in step ST2 in FIG.

  First, the image analysis unit 101A sets the entire screen as a color information analysis region, and thereafter, there is no color region exceeding the threshold value, and the region is narrowed every time the process returns to step ST12. In this case, the color information analysis area before the change constitutes a first image area, and the color information analysis area after the change constitutes a second image area. In this case, for example, it is narrowed toward the center of the screen (see FIG. 3).

  In this case, for example, the image is narrowed toward the in-focus position on the screen based on the in-focus position information included in the additional information from the imaging unit 103 (see FIG. 4). Further, in this case, for example, the specific object is narrowed toward the detection position of the specific object on the screen based on the information on the detection position of the specific object included in the additional information from the imaging unit 103.

  Next, in step ST13, the image analysis unit 101A performs color frequency distribution analysis in the same manner as the processing performed by the image analysis unit 101 of the image processing apparatus 100 in FIG. 1 in step ST3 in FIG. That is, the image analysis unit 101A performs a process of assigning to one of a plurality of color regions for each pixel or for each block including a predetermined number of pixels, for example, 8 × 8 pixels. The image analysis unit 101A performs this distribution processing based on color information for each pixel or block.

  Next, in step ST14, the image analysis unit 101A determines whether there is a color region whose frequency exceeds a threshold value. When determining that there is no color region whose frequency exceeds the threshold (see FIG. 6), the image analysis unit 101A returns to step ST12 and changes the color information analysis region. In this case, the color information analysis area (second image area) after the change is narrower than the color information analysis area (first image area) before the change (see FIGS. 3 and 4).

  On the other hand, when determining that there is a color region whose frequency exceeds the threshold value (see FIGS. 7 and 8), the image analysis unit 101A determines whether or not there is a change in the imaging state in step ST15. When determining that there is no change, the image analysis unit 101A returns to step ST12, sets the color information analysis region to the initial state, that is, the entire screen, and repeats the same processing as described above.

  When determining that there is a change in the imaging state, the image analysis unit 101A proceeds to the process of step ST16. When the image analysis unit 101A first determines that there is a color region whose frequency exceeds the threshold value in step ST14 after starting the process in step ST11, the image analysis unit 101A immediately moves to the process in step ST16.

  In step ST <b> 16, the image analysis unit 101 </ b> A determines at least one color area as an extracted color area from among color areas whose frequency exceeds a threshold value, and outputs information on the extracted color area on the screen. This process is the same as the process performed by the image analysis unit 101 of the image processing apparatus 100 in FIG. 1 in step ST5 in FIG. As described above, the image analysis unit 101A proceeds to the process of step ST16 only when it is determined that there is a change in the imaging state except for the first after the process is started in step ST11. Thereby, the extracted color area to be determined is updated when the imaging state is changed.

  After the process of step ST16, the image analysis unit 101A returns to step ST12, sets the color information analysis region to the initial state, that is, the entire screen, and repeats the same process as described above.

  Returning to FIG. 9, the image processing unit 102 performs image processing on the captured image signal SVa based on the extracted color region determined by the image analysis unit 101 to obtain a processed image signal SVb. In this case, the image processing unit 102 performs image processing on the extracted color region and / or other regions other than the extracted color region of the captured image signal SVa. The image processing unit 102 performs, for example, a process of enhancing saturation on the extracted color region of the captured image signal SVa. In addition, the image processing unit 102 performs, for example, an achromatic color, that is, a process of setting the saturation to zero, with respect to other regions other than the extracted color region of the captured image signal SVa.

  The output unit 104 performs processing for outputting the processed image signal SVb output from the image processing unit 102 to the outside. For example, the output unit 104 records the processed image signal SVb as a JPEG image file on a recording medium such as a memory card.

  The operation of the digital still camera 100A shown in FIG. 9 will be described. A captured image signal SVa obtained by imaging the subject by the imaging unit 103 is supplied to the image analysis unit 101A and the image processing unit 102. Further, additional information Iadd including information on the focus position output from the imaging unit 103 and information on the detection position of the specific object is supplied to the image analysis unit 101A. In the image analysis unit 101, an extracted color region including at least a partial region in the image is determined using the color information of the captured image signal SVa, and the region information is supplied to the image processing unit 102.

  Then, the image processing unit 102 performs image processing on the captured image signal SVa based on the extracted color region determined by the image analysis unit 101A, and obtains a processed image signal SVb. In this case, the image processing unit 102 performs image processing on the extracted color region and / or other regions other than the extracted color region of the captured image signal SVa. For example, the effect of a so-called partial color is realized by performing the process of making an achromatic color on the other areas excluding the extracted color area of the captured image signal SVa.

  The processed image signal SVb obtained by the image processing unit 102 is supplied to the output unit 104. In the output unit 104, processing for outputting the processed image signal SVb to the outside is performed. For example, the output unit 104 records the processed image signal SVb as a JPEG image file on a recording medium such as a memory card.

  As described above, in the digital still camera 100A shown in FIG. 9, the image analysis unit 101A of the camera body 110 automatically determines at least one extraction color region using the color information of the captured image signal SVa. Therefore, the image processing unit 102 of the camera main body 110 can reliably perform image processing based on the extracted color area information on the captured image signal SVa. For example, a so-called partial color effect can be reliably realized by performing the process of making the achromatic color other than the extracted color area of the captured image signal SVa.

  In the digital still camera 100A shown in FIG. 9, when the image analysis unit 101A of the camera main body 110 cannot determine the extraction color region, the image information analysis region 101A is changed in a direction to narrow the color information analysis region, and the extraction color region is determined again. Perform the process. Therefore, at least one extracted color area can be automatically determined. At this time, when the image is narrowed toward the in-focus position (focus point), it is possible to determine a color region that suits the user as the extracted color region.

  In the digital still camera 100A shown in FIG. 9, the image analysis unit 101A of the camera main body 110 updates the determined extracted color region when the imaging state is changed. Therefore, the extracted color region determined by the image analysis unit 101A does not change unless the user explicitly changes the exposure mode or zoom operation from the user operation unit 113. Therefore, it is possible to avoid the extraction color region from changing one after another due to a minute angle of view shift or a subject motion unintended by the user.

  Note that, in the flowchart shown in FIG. 10, even when there is no change in the imaging state, the processing of step ST12 to step ST14 is repeated. However, only when there is a change in the imaging state, a processing procedure for performing the processing of step ST12 to step ST14 and determining the extraction color region may be used.

<3. Modification>
In the above-described embodiment, when there are a plurality of color regions whose frequencies exceed the threshold value (see FIG. 8), the image analysis units 101 and 101A, for example, one of the plurality of color regions having a higher frequency or a predetermined number It has been described that the number of color areas is determined as the extracted color area. As described above, when there are a plurality of color regions whose frequency exceeds a threshold value, it is possible to configure the user to select a color region to be determined as the extracted color region. An operation example of the image analysis unit 101A and the like in that case will be described.

  An operation example of the image analysis unit 101A and the like in that case will be described. For example, in the flowchart of FIG. 10, when the imaging state is changed in step ST15, the CPU 111 determines in step ST17 whether there are two or more color regions whose frequency exceeds the threshold value. When there is only one color area whose frequency exceeds the threshold value, the image analysis unit 101A immediately moves to the process of step ST16 and determines that color area as the extracted color area.

  On the other hand, when determining that there are two or more color regions whose frequency exceeds the threshold, in step ST18, the CPU 111 sets the top N regions (N is an integer of 2 or more) among the color regions as candidate color regions. Are displayed on the display unit 114. This prompts the user to select an extraction color area. FIG. 11 shows a display example of candidate color regions on the display unit 114 of the digital still camera 100A. In this example, three candidate color areas are displayed by rectangles filled with the colors.

  Next, in step ST19, based on the display on the display unit 114, the user operates the user operation unit 113 to select a color region to be determined as the extraction color region. In the example of FIG. 11, one color area on the left side is surrounded by a frame FL, and this color area is selected. After the user selection in step ST19, the image analysis unit 101A determines a predetermined number of color areas selected by the user as extraction color areas in step ST16.

  In this way, when there are a plurality of color regions whose frequency exceeds the threshold, the user can select a color region to be determined as the extracted color region, and thereby determine the color region that suits the user's preference as the extracted color region. It becomes possible.

  In the above description, the candidate color region is displayed on the display unit 114 of the digital still camera 100A, and the user operates the user operation unit 113 of the digital still camera 100A to select the color region to be determined as the extraction color region. Explained. However, the display unit that displays the candidate color area may be an external device. In addition, the operation unit that is selected and operated by the user may be an external device such as a remote controller or via a network.

  That is, the digital still camera 100A, which is an image processing apparatus, causes the display unit to display at least the top N areas (N is an integer of 2 or more) having the highest frequency among a plurality of color areas whose frequencies exceed the threshold. A function of a user selection acquisition unit that prompts the user to select an extraction color area based on the display on the display unit may be provided.

  In the embodiment described above, when there is no color region whose frequency exceeds the threshold value, the color region analysis region is sequentially narrowed toward the center of the screen, the in-focus position in the screen, or the like. However, this process is only an option, and it is not necessary to perform this process itself. In this case, for example, the threshold value is not used, and one or a predetermined number of color regions with the highest frequency are simply determined as the extracted color regions.

  In the above-described embodiment, the processing of the image analysis units 101 and 101A and the image processing unit 102 can be executed by software as well as by hardware. When processing by software is executed, a program in which a processing sequence is recorded is installed in a memory in a computer incorporated in dedicated hardware and executed. Alternatively, the program can be installed and executed on a general-purpose computer capable of executing various processes.

Moreover, this technique can also take the following structures.
(1) An extracted color area determination unit that performs processing for determining an extracted color area including at least a partial area in the image using color information of the input image signal;
An image processing unit that performs image processing on the extracted color region determined by the extracted color region determining unit and / or other regions other than the extracted color region of the input image signal to obtain an output image signal; An image processing apparatus.
(2) The extracted color area determining unit performs a process of determining the extracted color area in a second image area narrower than the first image area when the extracted color area cannot be determined in the first image area. The image processing apparatus according to (1).
(3) In the first image area, the extracted color area determination unit performs a process of allocating to one of a plurality of color areas for each pixel or for each block including a predetermined number of pixels, and then the frequency is set to a threshold value. When there is a color area that exceeds, at least one color area of the color areas is determined as the extracted color area, and when there is no area whose frequency exceeds the threshold, in the second image area that is narrower than the first image area The image processing apparatus according to (2), wherein a process for determining the extracted color region is performed.
(4) The image according to (2) or (3), wherein the extracted color area determination unit sets the second image area as an image area in which the first image area is narrowed toward a screen center. Processing equipment.
(5) The extracted color area determination unit sets the second image area as an image area in which the first image area is narrowed toward a focus position in the screen. (2) or (3) An image processing apparatus according to 1.
(6) The extracted color area determination unit performs a process of allocating to any one of a plurality of color areas for each pixel or for each block including a predetermined number of pixels in the predetermined image area, and performs the extraction based on the frequency of each color area The image processing apparatus according to (1) or (2), wherein an area is determined.
(7) The extracted color region determination unit determines a predetermined number of color regions as the extracted color region from the higher frequency when there are a plurality of color regions whose frequency exceeds a threshold value. Image processing device.
(8) The image processing apparatus according to (6), wherein the extracted color area determination unit prompts the user to select the extracted color area when there are a plurality of color areas whose frequency exceeds a threshold.
(9) Display a high-frequency upper N area (N is an integer of 2 or more) among the plurality of color areas with the frequency exceeding the threshold as a candidate color area on the display unit,
The image processing apparatus according to (8), further including: a user selection acquisition unit that prompts the user to select the extracted color area based on the display of the display unit.
(10) The image processing device according to any one of (1) to (9), wherein the extracted color region determining unit updates the determined extracted color region when an imaging condition of the input image signal changes. .
(11) An extraction color region determination step for performing processing for determining an extraction color region including at least a partial region in the image using color information of the input image signal;
An image processing step of obtaining an output image signal by performing image processing on the extracted color region determined in the extracted color region determination step and / or other regions excluding the extracted color region of the input image signal; An image processing method.
(12) The computer
Extracted color area determining means for performing processing for determining an extracted color area including at least a partial area in the image using color information of the input image signal;
Image processing means for obtaining an output image signal by performing image processing on the extracted color area determined by the extracted color area determining means and / or other areas excluding the extracted color area of the input image signal. Program to function.
(13) an imaging unit;
An extraction color region determination unit that performs processing for determining an extraction color region including at least a partial region in the image using color information of the captured image signal obtained by the imaging unit;
An image processing unit that performs image processing on the extracted color region determined by the extracted color region determination unit and / or other regions other than the extracted color region of the captured image signal to obtain a processed image signal;
An imaging apparatus comprising: a recording unit that records a processed image signal obtained by the image processing unit on a recording medium.

DESCRIPTION OF SYMBOLS 100 ... Image processing apparatus 100A ... Digital still camera 101, 101A ... Image analysis part 102 ... Image processing part 103 ... Imaging part 104 ... Output part 110 ... Camera body part 111 ... CPU
112 ... Memory 113 ... User operation unit 114 ... Display unit

Claims (13)

An extraction color region determination unit that performs processing for determining an extraction color region including at least a partial region in the image using color information of the input image signal;
An image processing unit that performs image processing on the extracted color region determined by the extracted color region determining unit and / or other regions other than the extracted color region of the input image signal to obtain an output image signal; An image processing apparatus. The extracted color area determination unit performs a process of determining the extracted color area in a second image area narrower than the first image area when the extracted color area cannot be determined in the first image area. An image processing apparatus according to 1. In the first image area, the extracted color area determination unit performs a process of allocating to one of a plurality of color areas for each pixel or for each block including a predetermined number of pixels, and then the color area whose frequency exceeds a threshold value When there is an area, at least one color area is determined as the extracted color area, and when there is no area whose frequency exceeds a threshold value, the extracted color in the second image area narrower than the first image area The image processing apparatus according to claim 2, wherein a process for determining an area is performed. The image processing apparatus according to claim 2, wherein the extraction color area determination unit sets the second image area as an image area in which the first image area is narrowed toward a screen center. The image processing apparatus according to claim 2, wherein the extraction color area determination unit sets the second image area as an image area in which the first image area is narrowed toward a focus position on the screen. The extraction color area determination unit performs a process of allocating to a plurality of color areas for each pixel or for each block including a predetermined number of pixels in a predetermined image area, and determines the extraction area based on the frequency of each color area The image processing apparatus according to claim 1. The image processing device according to claim 6, wherein when there are a plurality of color regions whose frequency exceeds a threshold, the extracted color region determining unit determines a predetermined number of color regions as the extracted color region in descending order of frequency. The image processing apparatus according to claim 6, wherein the extracted color area determination unit prompts the user to select the extracted color area when there are a plurality of color areas whose frequency exceeds a threshold value. Of the plurality of color regions whose frequency exceeds the threshold, the top N regions (N is an integer greater than or equal to 2) are displayed as candidate color regions on the display unit,
The image processing apparatus according to claim 8, further comprising: a user selection acquisition unit that prompts the user to select the extracted color area based on the display of the display unit. The image processing apparatus according to claim 1, wherein the extracted color region determining unit updates the determined extracted color region when an imaging condition of the input image signal changes. An extraction color region determination step for performing processing for determining an extraction color region including at least a partial region in the image using color information of the input image signal;
An image processing step of obtaining an output image signal by performing image processing on the extracted color region determined in the extracted color region determination step and / or other regions excluding the extracted color region of the input image signal; An image processing method. Computer
Extracted color area determining means for performing processing for determining an extracted color area including at least a partial area in the image using color information of the input image signal;
Image processing means for obtaining an output image signal by performing image processing on the extracted color area determined by the extracted color area determining means and / or other areas excluding the extracted color area of the input image signal. Program to function. An imaging unit;
An extraction color region determination unit that performs processing for determining an extraction color region including at least a partial region in the image using color information of the captured image signal obtained by the imaging unit;
An image processing unit that performs image processing on the extracted color region determined by the extracted color region determination unit and / or other regions other than the extracted color region of the captured image signal to obtain a processed image signal;
An imaging apparatus comprising: a recording unit that records a processed image signal obtained by the image processing unit on a recording medium.