JP2004248048A - Device and program for generating video - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a video generating device and a video generation program which are capable of generating video of high image quality with pseudo color and a pseudo signal suppressed even though there is a level difference in color and brightness in the vertical direction. <P>SOLUTION: All RGB data are read from an image pickup element in a single horizontal transfer in the order of "RGBGRGBG...,". A color interpolation processing part performs either one-line color interpolation processing that uses data read in the single horizontal transfer or two-line color interpolation processing that uses data read in two horizontal transfers. In a resolution priority mode, if there is a brightness (Y) boundary in the vertical direction, the one-line interpolation processing is selected, and if there is a color boundary in the vertical direction, the two-line color interpolation processing is selected. Meanwhile, in a pseudo color reduction priority mode or an unset mode, if there is a color boundary, the two-line color interpolation processing is selected, and in the other modes, the one-line interpolation processing is selected. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a video generation apparatus and a video generation program that generate high-quality video while suppressing false signals and false colors.
[0002]
[Prior art]
One conventional imaging device has a plurality of light receiving portions that perform photoelectric conversion arranged at the same arrangement pitch and at positions shifted in the row direction and the column direction by a half of the arrangement pitch. . As shown in FIG. 5, on the image pickup device having such an arrangement (referred to as “honeycomb arrangement”), a G (green) filter and an R (red) are arranged in accordance with the position of each light receiving unit in adjacent rows. For example, a color filter composed of filters in which B and B (blue) are alternately arranged is provided. All the RGB data can be read out in the order of “RGBGRGBG...” By one horizontal transfer from the image pickup element having the honeycomb arrangement.
[0003]
When moving image shooting is performed using the image sensor, color interpolation processing may be performed using RGB data (one line of input data) read out by one horizontal transfer. For example, in one horizontal transfer, “R₀, G₁, B₂, G₃, R₄, G₅, B₆, G₇When the input data “is obtained, the color interpolation data r, g, and b shown below are generated for each pixel data.
[0004]
<Input data>
R_k, G_{k + 1}, B_{k + 2}, G_{k + 3}, R_{k + 4}, G_{k + 5}, B_{k + 6}, G_{k + 7}
<Color interpolation data>
r_n, R_{n + 1}, R_{n + 2}, R_{n + 3}
g_n, G_{n + 1}, G_{n + 2}, G_{n + 3}
b_n, B_{n + 1}, B_{n + 2}, B_{n + 3}
(N = k, k + 4, k + 8 ...)
However,
Pixel data R_kThe color interpolation data for is r_k, G_k, B_k
Pixel data G_{k + 1}The color interpolation data for is r_{k + 1}, G_{k + 1}, B_{k + 1}
Pixel data B_{k + 2}The color interpolation data for is r_{k + 2}, G_{k + 2}, B_{k + 2}
Pixel data G_{k + 3}The color interpolation data for is r_{k + 3}, G_{k + 3}, B_{k + 3}
It is.
[0005]
In addition,
r_k= R_k
r_{k + 1}= (3R_k+ R_{k + 4}) / 4
r_{k + 2}= (R_k+ R_{k + 4}) / 2
r_{k + 3}= (R_k+ 3R_{k + 4}) / 4
g_k= (G_k-1+ G_{k + 1}) / 2
g_{k + 1}= (G_k-1+ 2G_{k + 1}+ G_{k + 3}) / 4
g_{k + 2}= (G_{k + 1}+ G_{k + 3}) / 2
g_{k + 3}= (G_{k + 1}+ 2G_{k + 3}+ G_{k + 5}) / 4
b_k= (B_k-2+ B_{k + 2}) / 2
b_{k + 1}= (R_k-2+ 3R_{k + 2}) / 4
b_{k + 2}= B_{k + 2}
b_{k + 3}= (3R_{k + 2}+ R_{k + 6}) / 4
[0006]
[Patent Document 1]
JP 2002-199411 A
[0007]
[Problems to be solved by the invention]
However, when color interpolation processing using RGB data (one line of input data) read out by one horizontal transfer is performed on a video having a difference in level of color and brightness in the vertical direction, the RG line Since the RGB color level and luminance level are different at the boundary between the G line and the G line, there is a problem that generation of false colors and false signals cannot be avoided.
[0008]
The present invention has been made in view of the above-described conventional problems, and can generate a high-quality video in which false colors and false signals are suppressed even when there is a difference in level of color and brightness in the vertical direction. An object is to provide a video generation device and a video generation program.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, an image generation apparatus according to the present invention includes an imaging unit that outputs all RGB data in one horizontal transfer, and a predetermined color for each pixel data output from the imaging unit. Color interpolation processing means for performing interpolation processing, YC conversion means for YC conversion of each pixel data subjected to color interpolation processing by the color interpolation processing means, and a color difference between two lines adjacent in the vertical direction of the imaging region by the imaging means Based on the result of accumulating the level difference for the predetermined area, the color interpolation processing unit uses the pixel data output from the imaging unit in one horizontal transfer for the area corresponding to the predetermined area of the next frame. The one-line color interpolation processing and the two-line color interpolation processing using the pixel data output from the image pickup means in two horizontal transfers are determined, and the color interpolation instructed to the color interpolation processing means is determined. A processing method decision unit, wherein the color interpolation process method determining unit color determined by the interpolation processing and YC conversion to generate a video from the conducted data.
[0010]
Thus, one-line color interpolation processing or two-line color interpolation processing is performed according to the color difference level difference between two lines. In the two-line color interpolation process, color interpolation is performed using pixel data of two lines, so that even if there is a difference in luminance or color level in the vertical direction, the false color or false signal of the edge can be reduced. As a result, even if there is a color difference level difference in the vertical direction, it is possible to generate a high-quality video in which false colors are suppressed.
[0011]
Further, in the video generation device according to the present invention, the color interpolation processing method determination means accumulates the absolute value of the color difference level difference between the two lines for the predetermined area, and averages the number of pixels constituting the predetermined area. The average color difference level difference obtained by the comparison is compared with a predetermined color difference value, and if the average color difference level difference is equal to or greater than the predetermined color difference value, the two-line color interpolation process is determined. If it is less than the predetermined value, it is determined to perform the one-line color interpolation process. Therefore, if the color difference level difference between the two lines is large, the two-line color interpolation process is performed, so that an image with reduced false colors can be generated.
[0012]
Further, in the video generation device according to the present invention, the color interpolation processing method determining means may calculate the result of accumulating the color difference level difference between the two lines for the predetermined area and the luminance level difference between the two lines for the predetermined area. Based on the accumulated result, the color interpolation processing means determines whether to perform the one-line color interpolation process or the two-line color interpolation process for the area corresponding to the predetermined area of the next frame, Instructs the color interpolation processing means.
[0013]
As described above, the one-line color interpolation process or the two-line color interpolation process is performed according to both the color difference level and the luminance level difference between the two lines. Therefore, even when there is a color difference or a luminance level difference in the vertical direction, a high-quality video with suppressed false colors or false signals can be generated.
[0014]
Also, in the video generation device according to the present invention, the color interpolation processing method determination unit accumulates absolute values of luminance level differences between the two lines for the predetermined area, and averages the number of pixels constituting the predetermined area. The average luminance level difference obtained by converting to a predetermined luminance value is determined, and if the average luminance level difference is equal to or larger than the predetermined luminance value, it is determined to perform the one-line color interpolation process. If it is less than the predetermined value, it is desirable to compare the color difference level difference with the color difference predetermined value.
[0015]
In the video generation apparatus according to the present invention, the predetermined area is an area for all lines constituting one line, a plurality of lines, or one frame in the horizontal direction of the imaging area by the imaging means. Therefore, it is possible to select whether to perform one-line color interpolation processing or two-line color interpolation processing for each line, a plurality of lines, or frames.
[0016]
The video generation program according to the present invention is a color interpolation processing unit that performs predetermined color interpolation processing on each pixel data output from an imaging unit that outputs all RGB data in one horizontal transfer. YC conversion means for YC converting each pixel data subjected to color interpolation processing by the color interpolation processing means, and a result obtained by accumulating a color difference level difference between two adjacent lines in the vertical direction of the imaging area by the imaging means for a predetermined area. Based on this, the color interpolation processing means performs one-line color interpolation processing using the pixel data output from the imaging means in one horizontal transfer and two times for an area corresponding to the predetermined area of the next frame. Color interpolation processing method determining means for determining which of two-line color interpolation processing using pixel data output from the imaging means in horizontal transfer is to be performed and instructing the color interpolation processing means To function as, the color interpolation process method determining unit color determined by the interpolation processing and YC conversion to generate a video from the conducted data.
[0017]
Also, in the video generation program according to the present invention, the color interpolation processing method determination means accumulates the absolute value of the color difference level difference between the two lines for the predetermined area, and averages the number of pixels constituting the predetermined area. The average color difference level difference obtained by the comparison is compared with a color difference predetermined value, and if the average color difference level difference is greater than or equal to the color difference predetermined value, it is determined to perform the two-line color interpolation process, and the average color difference level difference is the color difference If it is less than the predetermined value, it is determined to perform the one-line color interpolation process.
[0018]
Further, in the video generation program according to the present invention, the color interpolation processing method determining means may calculate the result of accumulating the color difference level difference between the two lines for the predetermined area and the luminance level difference between the two lines for the predetermined area. Based on the accumulated result, the color interpolation processing means determines whether to perform the one-line color interpolation process or the two-line color interpolation process for the area corresponding to the predetermined area of the next frame, Instructs the color interpolation processing means.
[0019]
Further, in the video generation program according to the present invention, the color interpolation processing method determination unit accumulates absolute values of luminance level differences between the two lines for the predetermined area and averages the number of pixels constituting the predetermined area. The average luminance level difference obtained by converting to a predetermined luminance value is determined, and if the average luminance level difference is equal to or larger than the predetermined luminance value, it is determined to perform the one-line color interpolation process, and the average luminance level difference is the luminance If it is less than a predetermined value, the color difference level difference is compared with the color difference predetermined value.
[0020]
Further, in the video generation program according to the present invention, the predetermined area is an area for all lines constituting one line, a plurality of lines, or one frame in the horizontal direction of the imaging area by the imaging means.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a video generation apparatus according to the present invention will be described below in detail with reference to the drawings. In the following description, the video generation device according to the present invention will be described in detail. However, since the video generation program according to the present invention is a program for operating the video generation device, the description thereof will be described below. included. The video generation apparatus according to the present embodiment is described as being provided in a digital camera or the like equipped with a moving image function.
[0022]
Hereinafter, the configuration of the digital camera of the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing a schematic configuration of the digital camera of the present embodiment. As shown in the figure, the digital camera according to the present embodiment corresponds to an imaging unit 1, an analog signal processing unit 2, an A / D conversion unit 3, and a video generation device corresponding to the imaging means in the claims. A digital signal processing unit 6, a compression / decompression processing unit 7, a display unit 8, a system control unit 9, an internal memory 10, a media interface 11, a recording medium 12, and an operation unit 13. Has been. The digital signal processing unit 6, compression / decompression processing unit 7, display unit 8, system control unit 9, internal memory 10 and media interface 11 are connected to a system bus 20.
[0023]
The imaging unit 1 captures a subject with an optical system such as a photographing lens and an imaging element such as a CCD image sensor, and outputs an analog imaging signal. Note that in the imaging device such as a CCD image sensor used in the present embodiment, a plurality of light receiving portions that perform photoelectric conversion have the same arrangement pitch and are ½ the arrangement pitch in the row direction and the column direction. They are arranged at shifted positions. As shown in FIG. 5, on the image pickup device having such an arrangement (referred to as “honeycomb arrangement”), a G (green) filter and an R (red) are arranged in accordance with the position of each light receiving unit in adjacent rows. For example, a color filter composed of filters in which B and B (blue) are alternately arranged is provided.
[0024]
When light is incident on the image sensor through the color filter, an analog voltage signal based on signal charges accumulated with respect to the light is output from the image sensor. Note that all the RGB data is output in the order of “RGBGRGBG...” By one horizontal transfer from the image pickup element having the honeycomb arrangement. The signal output from the imaging unit 1 is sent to the analog signal processing unit 2, subjected to predetermined analog signal processing, converted into a digital signal by the A / D conversion unit 3, and then sent to the digital signal processing unit 6. .
[0025]
The digital signal processing unit 6 performs digital signal processing on the digital data from the A / D conversion unit 4 according to the operation mode set by the operation unit 12. The processing performed by the digital signal processing unit 6 includes white balance adjustment processing (gain adjustment), gamma correction processing, color interpolation processing (synchronization processing), YC conversion processing, and the like. The digital signal processing unit 6 is configured by a DSP, for example.
[0026]
The compression / decompression processing unit 7 performs compression processing on the YC data obtained by the digital signal processing unit 6 and performs decompression processing on the compressed image data obtained from the recording medium 12. In addition, the display unit 8 displays an image or moving image obtained by decompressing an image or moving image that has been photographed and subjected to digital signal processing or compressed data recorded on the recording medium 12. The display unit 8 can also display a through image at the time of shooting, various states of the digital camera, information on operations, and the like.
[0027]
The internal memory 10 is, for example, a DRAM, and is used as a work memory for the digital signal processing unit 6 and the system processing unit 9 as well as a buffer memory that temporarily stores captured image data recorded on the recording medium 12 and a display. It is also used as a buffer memory for display image data to the unit 8. The media interface 11 inputs / outputs data to / from a recording medium 12 such as a memory card.
[0028]
The system control unit 9 is mainly configured by a processor that operates according to a predetermined program, and controls the entire digital camera including a photographing operation. The operation unit 13 performs various operations when the digital camera is used. The operation unit 13 performs an operation mode (shooting mode, playback mode, etc.) of the digital camera, a shooting method at the time of shooting, shooting conditions, settings, and the like. Note that the operation unit 13 also includes a release button for starting a shooting operation.
[0029]
Next, the digital signal processing unit 6 included in the digital camera of the present embodiment will be described in detail with reference to FIG. FIG. 2 is a block diagram showing an internal configuration of the digital signal processing unit 6 provided in the digital camera of the present embodiment. It should be noted that description of blocks that perform white balance adjustment processing and gamma correction processing performed by the digital signal processing unit 6 is omitted, and is not described in the drawing (FIG. 2). Therefore, in the following description, only the color interpolation process (synchronization process), the YC conversion process, and the like in this embodiment will be described.
[0030]
As shown in FIG. 2, the digital signal processing unit 6 of the present embodiment includes a color interpolation processing unit 101 corresponding to the color interpolation processing unit in the claims, a YC conversion unit 103 corresponding to the YC conversion unit, and a color And a color interpolation processing method determination unit 105 corresponding to the interpolation processing method determination means. The color interpolation processing unit 101 performs color interpolation on the digital data from the A / D conversion unit 4. More specifically, color interpolation data is generated for each pixel data of RGB.
[0031]
Note that all RGB data is read from the image sensor in the order of “RGBGRGBG...” In one horizontal transfer, but in the color interpolation processing unit 101 of the present embodiment, data read out in one horizontal transfer ( Either color interpolation processing using one line input data) or color interpolation processing using two horizontal transfer data (two line input data) is performed. In the following description, color interpolation processing using one line of input data is referred to as “one line color interpolation processing”, and color interpolation processing using two lines of input data is referred to as “two line color interpolation processing”.
[0032]
For example, in one horizontal transfer, “R_k, G_{k + 1}, B_{k + 2}, G_{k + 3}, R_{k + 4}, G_{k + 5}, B_{k + 6}, G_{k + 7}In the one-line color interpolation process, the following color interpolation data r, g, and b are generated for each pixel data.
[0033]
"One line color interpolation process"
<Input data>
R_k, G_{k + 1}, B_{k + 2}, G_{k + 3}, R_{k + 4}, G_{k + 5}, B_{k + 6}, G_{k + 7}
<Color interpolation data>
r_n, R_{n + 1}, R_{n + 2}, R_{n + 3}
g_n, G_{n + 1}, G_{n + 2}, G_{n + 3}
b_n, B_{n + 1}, B_{n + 2}, B_{n + 3}
(N = k, k + 4, k + 8 ...)
However,
Pixel data R_kThe color interpolation data for is r_k, G_k, B_k
Pixel data G_{k + 1}The color interpolation data for is r_{k + 1}, G_{k + 1}, B_{k + 1}
Pixel data B_{k + 2}The color interpolation data for is r_{k + 2}, G_{k + 2}, B_{k + 2}
Pixel data G_{k + 3}The color interpolation data for is r_{k + 3}, G_{k + 3}, B_{k + 3}
It is.
[0034]
In addition,
r_k= R_k
r_{k + 1}= (3R_k+ R_{k + 4}) / 4
r_{k + 2}= (R_k+ R_{k + 4}) / 2
r_{k + 3}= (R_k+ 3R_{k + 4}) / 4
g_k= (G_k-1+ G_{k + 1}) / 2
g_{k + 1}= (G_k-1+ 2G_{k + 1}+ G_{k + 3}) / 4
g_{k + 2}= (G_{k + 1}+ G_{k + 3}) / 2
g_{k + 3}= (G_{k + 1}+ 2G_{k + 3}+ G_{k + 5}) / 4
b_k= (B_k-2+ B_{k + 2}) / 2
b_{k + 1}= (R_k-2+ 3R_{k + 2}) / 4
b_{k + 2}= B_{k + 2}
b_{k + 3}= (3R_{k + 2}+ R_{k + 6}) / 4
[0035]
On the other hand, in the first horizontal transfer, “R_ik, G_{ik + 1}, B_{ik + 2}, G_{ik + 3}, R_{ik + 4}, G_{ik + 5}, B_{ik + 6}, G_{ik + 7}”Is obtained, and“ B ”is obtained in the second horizontal transfer._{i + 1k}, G_{i + 1k + 1}, R_{i + 1k + 2}, G_{i + 1k + 3}, B_{i + 1k + 4}, G_{i + 1k + 5}, R_{i + 1k + 6}, G_{i + 1k + 7}In the two-line color interpolation process, the following color interpolation data r, g, and b are generated for each pixel data obtained by the first horizontal transfer.
[0036]
"2-line color interpolation"
<Input data>
R_ik, G_{ik + 1}, B_{ik + 2}, G_{ik + 3}, R_{ik + 4}, G_{ik + 5}, B_{ik + 6}, G_{ik + 7}
B_{i + 1k}, G_{i + 1k + 1}, R_{i + 1k + 2}, G_{i + 1k + 3}, B_{i + 1k + 4}, G_{i + 1k + 5}, R_{i + 1k + 6}, G_{i + 1k + 7}
<Color interpolation data>
r_n, R_{n + 1}, R_{n + 2}, R_{n + 3}
g_n, G_{n + 1}, G_{n + 2}, G_{n + 3}
b_n, B_{n + 1}, B_{n + 2}, B_{n + 3}
(N = k, k + 4, k + 8 ...)
However,
Pixel data R_ikThe color interpolation data for is r_k, G_k, B_k
Pixel data G_{ik + 1}The color interpolation data for is r_{k + 1}, G_{k + 1}, B_{k + 1}
Pixel data B_{ik + 2}The color interpolation data for is r_{k + 2}, G_{k + 2}, B_{k + 2}
Pixel data G_{ik + 3}The color interpolation data for is r_{k + 3}, G_{k + 3}, B_{k + 3}
It is.
[0037]
In addition,
r_k= (R_{i + 1k-2}+ 2R_ik+ R_{i + 1k + 2}) / 4
r_{k + 1}= (R_ik+ R_{i + 1k + 2}) / 2
r_{k + 2}= (R_ik+ 2R_{i + 1k + 2}+ R_{ik + 4}) / 4
r_{k + 3}= (R_{i + 1k + 2}+ R_{ik + 4}) / 2
g_k= (G_ik-1+ G_{ik + 1}) / 2
g_{k + 1}= (G_ik-1+ 2G_{ik + 1}+ G_{ik + 3}) / 4
g_{k + 2}= (G_{ik + 1}+ G_{ik + 3}) / 2
g_{k + 3}= (G_{ik + 1}+ 2G_{ik + 3}+ G_{ik + 5}) / 4
b_k= (B_ik-2+ 2B_{i + 1k}+ B_{ik + 2}) / 4
b_{k + 1}= (B_{i + 1k}+ B_{ik + 2}) / 2
b_{k + 2}= (B_{i + 1k}+ 2B_{ik + 2}+ B_{i + 1k + 4}) / 4
b_{k + 3}= (B_{ik + 2}+ B_{i + 1k + 4}) / 2
[0038]
In the above-described two-line color interpolation processing, color interpolation processing is performed on the B pixel data using the data read in the first horizontal transfer, but in the first and second horizontal transfer. Color interpolation processing may be performed using the read data (two-line input data).
[0039]
The YC conversion unit 103 converts the RGB data color-interpolated by the color interpolation processing unit 101 into luminance (Y) data and color difference (C) data. The data (YC data) converted by the YC conversion unit 103 is stored in the internal memory 10 via the system bus 20, converted to RGB data, and displayed on the display unit 8. Similar YC data is also sent to the color interpolation processing method determination unit 105.
[0040]
The color interpolation processing method determination unit 105 determines that the color interpolation processing unit 101 performs one line for the next frame based on each level difference in luminance and color difference between two adjacent lines in the vertical direction of the imaging region by the imaging unit 1. Whether to perform color interpolation processing or 2-line color interpolation processing is determined, and the color interpolation processing unit 101 is instructed. FIG. 3 is a block diagram showing an internal configuration of the color interpolation processing method determination unit 105. As shown in the figure, the color interpolation processing method determination unit 105 includes line memories 201a and 201b, difference calculation units 203a and 203b, absolute value calculation units 205a and 205b, integration units 207a and 207b, registers 209a, 209b, averaging units 211a and 211b, and a determination processing unit 213.
[0041]
Note that the line memory 201a, the difference calculation unit 203a, the absolute value calculation unit 205a, the integration unit 207a, the register 209a, and the averaging unit 211a are parts for obtaining the vertical gradient (luminance gradient) of the Y data. 201b, the difference calculation unit 203b, the absolute value calculation unit 205b, the integration unit 207b, the register 209b, and the averaging unit 211b are portions for obtaining a vertical gradient (color difference gradient) of the C data.
[0042]
The line memory 201a stores Y data of each pixel data obtained by one horizontal transfer. In addition, the difference calculation unit 203a subtracts the luminance level indicated by the Y data of each pixel data obtained next from the luminance level indicated by the Y data of each pixel data stored in the line memory 201a, so that it is adjacent in the vertical direction. The brightness level difference (ΔY) between matching lines is calculated. The absolute value calculator 205a calculates the absolute value (| ΔY |) of the luminance level difference (ΔY) obtained by the difference calculator 203a.
[0043]
The accumulating unit 207a accumulates the absolute value of the luminance level difference obtained from the absolute value calculating unit 205a by the predetermined number of lines accumulated in the register 209. Therefore, the cumulative luminance level difference that can be expressed by “Σ | ΔY |” is output from the accumulating unit 207a. Further, the averaging unit 211a divides the accumulated luminance level difference (Σ | ΔY |) obtained from the integrating unit 207a by the number (x) indicated by “the number of accumulated lines × the number of pixels of one line”. An average luminance level difference (Σ | ΔY | / x) per pixel is obtained.
[0044]
On the other hand, the line memory 201b, the difference calculation unit 203b, the absolute value calculation unit 205b, the integration unit 207b, the register 209b, and the averaging unit 211b are configured so that the line memory 201a, the difference calculation unit 203a, the absolute value calculation unit 205a, An average color difference level difference (Σ | ΔC | / x) per pixel is obtained by performing the same operations as those of the accumulating unit 207a, the register 209a, and the averaging unit 211a.
[0045]
It should be noted that how many lines the absolute value (| ΔY |) of the luminance level difference is integrated by the integration units 207a and 207b is variable depending on the setting, and for one line, a plurality of lines, and a line constituting one frame. You can choose from. For example, when integrating the absolute value of the luminance level difference for two lines, the data for one line is accumulated in the register 209 and reset every two lines.
[0046]
The average luminance level difference (Σ | ΔY | / x) and the average color difference level difference (Σ | ΔC | / x) thus obtained are input to the determination processing unit 213. The determination processing unit 213 makes a different determination depending on whether the “resolution priority mode”, “false color reduction priority mode”, or “unset mode” is selected by the user of the digital camera of this embodiment. The determination processing unit 213 compares the average luminance level difference “Σ | ΔY | / x” with a predetermined threshold “y”, or compares the average color difference level difference “Σ | ΔC | / x” with a predetermined threshold. By comparing “c”, it is determined whether the color interpolation processing unit 101 performs the one-line color interpolation processing or the two-line color interpolation processing based on the respective magnitude relations, and the color interpolation processing unit 101 is instructed. doing.
[0047]
Hereinafter, the determination process performed by the determination processing unit 213 will be described in detail with reference to the flowchart shown in FIG. FIG. 4 is a flowchart illustrating the determination process performed by the determination processing unit 213. First, it is determined which mode the digital camera of this embodiment is set to (step S101). As a result of the determination in step S101, if the resolution priority mode is set, the process proceeds to step S111. If the false color reduction priority mode or the unset mode is set, the process proceeds to step S121.
[0048]
In step S111, the average luminance level difference “Σ | ΔY | / x” is compared with a predetermined threshold value “y”. As a result of the comparison, if Σ | ΔY | / x ≧ y, the one-line color interpolation processing is determined, and if Σ | ΔY | / x <y, the process proceeds to step S113. In step S113, the average color difference level difference “Σ | ΔC | / x” is compared with a predetermined threshold value “c”. As a result of the comparison, if Σ | ΔC | / x ≧ c, it is determined to perform 2-line color interpolation processing, and if Σ | ΔC | / x <c, it is determined to perform 1-line color interpolation processing. Thus, in the resolution priority mode, if there is a luminance boundary in the vertical direction, one-line color interpolation processing is selected, and if there is a color boundary in the vertical direction, two-line color interpolation processing is selected.
[0049]
On the other hand, in step S121, the average color difference level difference “Σ | ΔC | / x” is compared with a predetermined threshold value “c”. As a result of the comparison, if Σ | ΔC | / x ≧ c, the process proceeds to step S117 to decide to perform the two-line color interpolation process, and if Σ | ΔC | / x <c, the one-line color interpolation process is performed. decide. As described above, in the false color reduction priority mode or the non-setting mode, if there is a color boundary in the vertical direction, the 2-line color interpolation process is selected, and otherwise, the 1-line color interpolation process is selected.
[0050]
The determination processing unit 213 instructs the color interpolation processing unit 101 to perform the color interpolation processing determined in accordance with the rules according to the flowchart with respect to the line or region targeted for the next frame. That is, if the above determination process is performed for one line, an instruction is given to perform the determined color interpolation process for the corresponding line of the next frame. Further, if the above determination is made for a plurality of lines, an instruction is given to perform the determined color interpolation processing for the area constituted by the corresponding lines of the next frame. Further, if the above determination process is performed for the entire frame, an instruction is given to perform the determined color interpolation process for the entire next frame.
[0051]
As described above, according to the digital camera of the present embodiment, the color interpolation processing unit 101 for each frame constituting the video based on the level difference of luminance and color difference between lines adjacent in the vertical direction. It is determined whether to perform one-line color interpolation processing or two-line color interpolation processing, and the color interpolation processing unit 101 is instructed. In one-line color interpolation processing, color interpolation is performed using pixel data constituting one line, so that there is a problem that false colors and false signals are generated in the video if there is a difference in luminance or color level in the vertical direction. However, in the two-line color interpolation process, color interpolation is performed using pixel data of two lines, so that even if there is a difference in luminance or color level in the vertical direction, it is possible to reduce edge false colors and false signals. As a result, it is possible to generate a high-quality image in which false colors and false signals are suppressed even if the image has a luminance or color level difference in the vertical direction.
[0052]
Whether to perform one-line color interpolation processing or two-line color interpolation processing can be selected for each line of the frame, for each area, or for the entire frame. Therefore, it is possible to select whether to perform one-line color interpolation processing or two-line color interpolation processing for each desired region (one line, a plurality of lines, or the entire frame).
[0053]
【The invention's effect】
As described above, according to the video generation device and the video generation program according to the present invention, it is possible to generate a high-quality video that suppresses false colors and false signals even when there is a difference in level of color and brightness in the vertical direction. Can do.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of a digital camera according to an embodiment.
FIG. 2 is a block diagram showing an internal configuration of a digital signal processing unit included in the digital camera of the present embodiment.
FIG. 3 is a block diagram illustrating an internal configuration of a color interpolation processing method determination unit included in the digital signal processing unit.
FIG. 4 is a flowchart illustrating determination processing performed by a determination processing unit.
FIG. 5 is an explanatory diagram showing the arrangement of color filters provided on an image sensor with a honeycomb arrangement.
[Explanation of symbols]
1 Imaging unit
2 Analog signal processor
3 A / D converter
6 Digital signal processor
7 Compression / decompression processor
8 Display section
9 System controller
10 Internal memory
11 Media interface
12 Recording media
13 Operation part
101 Color interpolation processor
103 YC converter
105 color interpolation processing method determination unit
201a, 201b line memory
203a, 203b Difference calculation unit
205a, 205b Absolute value calculation unit
207a, 207b Integration unit
209a, 209b registers
211a, 211b Averaging unit
213 Determination processing unit

Claims (10)

Imaging means for outputting all RGB data in one horizontal transfer;
Color interpolation processing means for performing predetermined color interpolation processing on each pixel data output from the imaging means;
YC conversion means for YC converting each pixel data subjected to color interpolation processing by the color interpolation processing means;
Based on the result of accumulating the color difference level difference between two adjacent lines in the vertical direction of the imaging area by the imaging means for a predetermined area, the color interpolation processing means for the area corresponding to the predetermined area of the next frame, Either one-line color interpolation processing using pixel data output from the imaging unit in one horizontal transfer or two-line color interpolation processing using pixel data output from the imaging unit in two horizontal transfers Color interpolation processing method determining means for determining whether to instruct the color interpolation processing means;
An image generating apparatus for generating an image from data subjected to color interpolation processing and YC conversion determined by the color interpolation processing method determining means. The color interpolation processing method determining means includes
The absolute value of the color difference level difference between the two lines is accumulated for the predetermined area, and the average color difference level difference obtained by averaging with the number of pixels constituting the predetermined area is compared with the predetermined color difference value, and the average color difference level It is determined that the two-line color interpolation process is performed if the difference is greater than or equal to the color difference predetermined value, and the one-line color interpolation process is determined if the average color difference level difference is less than the color difference predetermined value. The video generation apparatus according to claim 1. The color interpolation processing method determining means includes
Based on the result of accumulating the color difference level difference between the two lines for the predetermined area and the result of accumulating the luminance level difference between the two lines for the predetermined area, for the area corresponding to the predetermined area of the next frame The video according to claim 1 or 2, wherein the color interpolation processing means determines whether to perform the one-line color interpolation processing or the two-line color interpolation processing, and instructs the color interpolation processing means. Generator. The color interpolation processing method determining means includes
The absolute value of the luminance level difference between the two lines is accumulated for the predetermined area, and the average luminance level difference obtained by averaging with the number of pixels constituting the predetermined area is compared with the predetermined luminance value, and the average luminance level If the difference is equal to or greater than the predetermined luminance value, the one-line color interpolation process is determined to be performed, and if the average luminance level difference is less than the predetermined luminance value, the color difference level difference is compared with the predetermined color difference value. The video generation apparatus according to claim 3. 5. The video according to claim 1, 2, 3, or 4, wherein the predetermined area is an area for all lines constituting one line, a plurality of lines, or one frame in a horizontal direction of an imaging area by the imaging means. Generator. Computer
Color interpolation processing means for performing predetermined color interpolation processing on each pixel data output from the imaging means for outputting all RGB data in one horizontal transfer;
YC conversion means for YC converting each pixel data subjected to color interpolation processing by the color interpolation processing means;
Based on the result of accumulating the color difference level difference between two adjacent lines in the vertical direction of the imaging area by the imaging means for a predetermined area, the color interpolation processing means for the area corresponding to the predetermined area of the next frame, Either one-line color interpolation processing using pixel data output from the imaging unit in one horizontal transfer or two-line color interpolation processing using pixel data output from the imaging unit in two horizontal transfers Determine whether to perform, and function as a color interpolation processing method determination means for instructing the color interpolation processing means,
An image generation program for generating an image from data subjected to color interpolation processing and YC conversion determined by the color interpolation processing method determination means. The color interpolation processing method determining means includes
The absolute value of the color difference level difference between the two lines is accumulated for the predetermined area, and the average color difference level difference obtained by averaging with the number of pixels constituting the predetermined area is compared with the predetermined color difference value, and the average color difference level It is determined that the two-line color interpolation process is performed if the difference is greater than or equal to the color difference predetermined value, and the one-line color interpolation process is determined if the average color difference level difference is less than the color difference predetermined value. The video generation program according to claim 6. The color interpolation processing method determining means includes
Based on the result of accumulating the color difference level difference between the two lines for the predetermined area and the result of accumulating the luminance level difference between the two lines for the predetermined area, for the area corresponding to the predetermined area of the next frame 8. The video according to claim 6, wherein the color interpolation processing unit determines whether to perform the one-line color interpolation processing or the two-line color interpolation processing, and instructs the color interpolation processing unit. Generation program. The color interpolation processing method determining means includes
The absolute value of the luminance level difference between the two lines is accumulated for the predetermined area, and the average luminance level difference obtained by averaging with the number of pixels constituting the predetermined area is compared with the predetermined luminance value, and the average luminance level If the difference is equal to or greater than the predetermined luminance value, the one-line color interpolation process is determined to be performed, and if the average luminance level difference is less than the predetermined luminance value, the color difference level difference is compared with the predetermined color difference value. The video generation program according to claim 8, wherein: 10. The video according to claim 6, 7, 8, or 9, wherein the predetermined area is an area for all lines constituting one line, a plurality of lines, or one frame in a horizontal direction of an imaging area by the imaging means. Generation program.

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