JPH06105333A - Picture signal processor - Google Patents

Abstract

PURPOSE:To output a black/white picture signal without deteriorating the signal by selecting a black/white picture signal processing means or a color picture signal processing means and processing the outputted picture signal. CONSTITUTION:A system controller 7 monitors a black/white picture signal processing mode command switch of an operation section 10 and throws changeover switches 11, 14 both to the position (a) when the color picture signal processing mode is set. When the black/white picture signal processing mode is set, the controller throws the changeover switches 11, 14 both to the position (b). Then a color picture signal processing circuit 12 or a black/white picture signal processing circuit 13 applies picture signal processing to picture data read from a picture memory 6 and a D/A converter 15 converts the signal into an analog signal as an output. When picture data reproduced from a recording medium are outputted as a black/white picture signal, the circuit 13 does not implement color separation processing but a gamma correction circuit 22 implements correction processing. Then the black/white picture signal is processed and outputted without being deteriorated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image signal processing device for processing an image signal.

[0002]

2. Description of the Related Art As a conventional image signal processing device for processing an image signal, a still video system for recording a still image signal on a recording medium such as a magnetic disk and reproducing the still image signal recorded on the recording medium. It has been known.

The still video system is an optical system, C
CD (Charge Coupled Device)
An image signal as an electric signal is formed by forming an image signal as an electric signal by capturing an image of an object with a video camera unit having an image sensor such as When the recorded image signal is analog-recorded on an analog recording medium such as a magnetic disk,
A predetermined analog signal processing is performed by an analog image signal processing circuit, FM modulation is performed, analog recording is performed on the magnetic disk, and the formed image signal is digitally recorded on a hard disk device or a semiconductor memory device such as a memory card. When digitally recording on a recording medium,
The formed image signal is sampled and held and converted into a digital image signal by analog / digital (A / D) conversion, and a predetermined digital signal processing is performed by a digital image signal processing circuit, and then the hard disk device. , Or a new system for digitally recording on a semiconductor memory device such as a memory card has been devised.

In particular, the system for digitally recording the image signal formed by the video camera section as described above is in the limelight as a promising system in the future because the image signal is hardly deteriorated by recording and reproducing.

An example of a digital image recording system for digitally recording the image signal formed by the video camera unit will be described below.

FIG. 3 shows a digital image recording system having a video camera unit having a single image pickup device.
An example of the arrangement of color filters provided on the image pickup surface of the image pickup element is shown. For example, as shown in FIG. 3, a green filter (G1 and G2 in the figure) and a red filter (in the figure) are provided for each pixel. R) and a blue filter (B in the figure) are formed so as to form one pixel block, and an image output from an image pickup device provided with such a color filter on the image pickup surface is formed. The signal is digitized by an A / D converter (not shown) to form a digital image signal, and then, in the color separation circuit 41 in the color image signal processing circuit shown in FIG. Signals and separate each signal into a low pass filter (L
The low frequency components are extracted through the PFs) 42, 43 and 44 and supplied to the adders 45, 46 and 47.

The digital image signal is also supplied to a white balance circuit 48. The white balance circuit 48 adjusts the white balance of each digital color component signal, and the white balance is adjusted for each digital color component. A luminance signal is formed from the signal in a matrix circuit 49, a high frequency component is extracted from the formed luminance signal through a high-pass filter (HPF) 50, and each digital color component is added in the adders 45, 46 and 47. The signal is added to the low frequency component of the signal, and is further subjected to gamma correction processing in gamma correction circuits 51, 52 and 53, and then recorded as digital image signal recording (not shown) as R, G and B digital color component signals. Output to the department.

[0008]

However, in the system as described above, for example, when the color of the object imaged by the video camera unit is black and white, R, G, and Each B digital color component signal has no color difference component, and the R, G, and B digital color component signal levels should be the same,
Each of the R, G, and B digital color component signals separated in the color separation circuit 41 is a part of the information amount of the original subject image (that is, the R and B component signals are ¼, and the G component signal is Has only one half), and the remaining part (that is, three-fourths for the R and B component signals and one half for the G component signal) is the interpolation filter in the color separation circuit 41. The white balance circuit 48 cannot accurately adjust the white balance of the interpolated portion because it is formed by the interpolation processing by

Therefore, the levels of the R, G, and B digital color component signals output from the adders 45, 46, and 47 are not exactly the same, and color difference components are generated.
The black and white digital image signals output from the adders 45, 46 and 47 are colored (so-called false colors), and the image quality is deteriorated.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an image signal processing apparatus capable of processing and outputting a monochrome image signal without degrading it.

[0011]

SUMMARY OF THE INVENTION An image signal processing apparatus according to the present invention generates an image signal having second and third color component signals having a smaller amount of information than a first color component signal corresponding to a predetermined color component. Image signal output means for outputting, a color image signal processing means for performing color image signal processing on the image signal output by the image signal output means, and an image signal output by the image signal output means. On the other hand, a color image signal processing means for performing black and white image signal processing, and either the color image signal processing means or the black and white image signal processing means is selected, and selected by the selected image signal processing means. An image signal processing selection means for processing the image signal output from the image signal output means, and an exclusive surface for the first color filter section corresponding to a predetermined color component. And a color filter having narrow second and third color filter units, and an image pickup unit that outputs an image signal by picking up an image of a subject, and a color image signal processing for the image signal output from the image pickup unit. A color image signal processing means for performing the image processing, and a color image signal processing means for performing the black and white image signal processing on the image signal output from the image capturing means, the color image signal processing means, or the monochrome image. Image signal processing selecting means for selecting any one of the signal processing means and processing the image signal output from the image pickup means by the selected image signal processing means, and a predetermined color. Image signal output means for outputting a color image signal or a monochrome image signal having second and third color component signals having a small amount of information with respect to the first color component signal corresponding to the component A color image signal processing means for performing color image signal processing on the image signal output from the image signal output means, and a monochrome image signal for the image signal output from the image signal output means. Color image signal processing means for performing processing, image signal determination means for determining whether the image signal output from the image signal output means is the color image signal or the monochrome image signal, and the determination result in the image signal determination means According to the above, either one of the color image signal processing means or the monochrome image signal processing means is selected, and the image signal output from the image signal output means is processed by the selected image signal processing means. And an image signal processing selection means.

[0012]

With the above arrangement, it is possible to process and output a monochrome image signal without deterioration.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a schematic structure of an image signal processing apparatus for digitally recording an image signal on a recording medium as an embodiment of the present invention, and FIG. 2 is a block diagram of the monochrome image processing circuit in FIG. It is the figure which showed schematic structure.

In FIG. 1, at the time of recording operation, a subject optical image obtained by picking up a subject passes through an optical system 1 composed of a lens and an exposure control system 2 composed of a shutter mechanism and a diaphragm mechanism. Then, an image is formed on the image pickup surface of the image pickup element 3, and photoelectrically converted by the image pickup element 3 to be converted into an image signal as an electric signal.
It is supplied to the sample and hold circuit 4.

Then, the image signal supplied from the image pickup device 3 is sampled and held in the sample and hold circuit 4, and the sampled and held image signal is digitized in the A / D converter 5 in the next stage. Is supplied to the image memory 6 as image data.

The writing and reading of the image data in the image memory 6 is controlled by a memory control circuit 8 which operates according to an instruction from the system controller 7, and the image data supplied from the A / D converter 5 is controlled. Are written in the image memory 6 by the memory control circuit 8.

Further, the memory control circuit 8 normally writes the image data supplied from the A / D converter 5 into the image memory 6 without compressing the image data as it is, but if necessary, It is also possible to compress the image data supplied from the A / D converter 5 to reduce the amount of information and then write the image data in the image memory 6.

As described above, the image data once written in the image memory 6 is ready for recording on the digital recording medium 8 constituted by a hard disk device or a semiconductor memory device such as a memory card. Then, it is read from the image memory 6 by the memory control circuit 8, supplied to the digital recording medium 8 and recorded.

The memory control circuit 8 normally reads the image data from the image memory 6 without decompressing the image data as it is, but if necessary, it reads the image data read from the image memory 6. It is also possible to expand the amount of information by performing expansion processing.

On the other hand, at the time of reproducing operation, the image data reproduced from the recording medium 9 is supplied to the image memory 6 and temporarily stored in accordance with an instruction from the system controller 7.

Further, the system controller 7 monitors the state of the monochrome image signal processing mode instruction switch in the operation section 10, and when the state of the switch does not indicate the monochrome image signal processing mode, that is, the color image signal processing mode. Switch, switch 1
1 and 14 are both connected to the side a in the figure, and the image memory 6
The color image signal processing circuit 12 having the same configuration as that of the circuit shown in FIG.
The analog (D / A) converter 15 outputs the data after being converted into analog.

Further, when the state of the monochrome image signal processing mode instruction switch in the operation section 10 indicates the monochrome image signal processing mode, the system controller 7 sets both the changeover switches 11 and 14 to b in the figure. 2 for the image data read out from the image memory 6 connected to the side of the black and white image signal processing circuit 1 shown in FIG.
3, the black-and-white image signal processing is performed, and the D / A converter 15 at the next stage converts the analog signal into an analog signal, which is then output.

The monochrome image signal processing circuit 13 is shown in FIG.
As shown in FIG. 4, the color separation circuit 41 does not separate the digital color component signals of R, G and B from the input image data like the color image signal processing circuit shown in FIG. After being supplied to the circuit 21, the white balance circuit 21 adjusts the white balance of each digital color component signal, and the gamma correction circuit 22 performs gamma correction processing.
It is constructed so as to be output as image data composed of each digital color component data of B.

As described above, the image signal processing apparatus according to this embodiment outputs the image data reproduced from the recording medium as a black and white image signal by the black and white image signal processing mode instruction switch provided in the operation section. When instructed to do so, the color image signal processing circuit does not perform the color separation processing performed in the color image signal processing circuit but adjusts the white balance as it is and performs gamma correction. The image data processed by the black-and-white image signal processing circuit is output as a digital color component signal of R, G, B to a display device, a printer device or the like, thereby preventing the occurrence of color misregistration or false color. However, there is an effect that it is possible to output a high-quality black and white image signal while suppressing the apparent resolution deterioration.

As one embodiment of the present invention, in the image signal processing apparatus shown in FIG. 1, the image data reproduced from the recording medium is reproduced by the black and white image signal processing mode instruction switch provided in the operation section. When it is instructed to output as a monochrome image signal, the monochrome image signal processing circuit is selected instead of the color image signal processing circuit. However, as in the image signal processing apparatus shown in FIG. If a data discriminating circuit 16 is provided and the image data reproduced by the image data discriminating circuit 16 from the recording medium 9 and once written in the image memory 6 is determined to represent a monochrome image, the image is discriminated. An instruction is sent from the data discriminating circuit 16 to the system controller 7, and the system controller 7 connects both the changeover switches 11 and 14 to the side b in the figure to automatically It may be configured so as to select the white black image signal processing circuit 13, in which the same effect can be obtained in this case.

FIG. 5 is a diagram showing a schematic configuration of an image signal processing apparatus for digitally recording an image signal on a recording medium as another embodiment of the present invention. In FIG. 5, the configuration shown in FIG. The same parts are denoted by the same reference numerals, and detailed description will be omitted.

By the way, in the apparatus shown in FIG. 5, the image data discriminating circuit 16 first reads out the image data reproduced from the recording medium 9 and once written in the image memory 6, and then reads out the image data from the image memory 6. By applying color separation processing to the read image data, R,
The B, G digital color component signals are separated, and the white balance is adjusted for the separated R, G, B digital color component signals in the same manner as in the color image processing described above.

The image data reproduced from the recording medium 9 is generated by, for example, a video camera section having a single image pickup device having a color filter as shown in FIG. When the recorded image signal is digitized and recorded on the recording medium 9,
Each digital color component signal of R, G1, G2, and B is extracted, and the extracted digital color component signal is used to perform interpolation processing during a period in which the digital color component signal does not exist. By forming the digital color component signals for one screen, the digital color component signals for a total of four screens are formed.

Then, the degree of correlation between the color component signals for one screen among the digital color component signals for the four screens formed and the digital color component signals for the other three screens is calculated, and the calculated correlations are calculated. If the degree exceeds a predetermined threshold, it is considered that the image data written in the image memory 6 indicates a color image, and if the calculated degree of correlation is smaller than the threshold. The image data written in the image memory 6 is regarded as indicating a monochrome image, and the information indicating the determination result is transmitted to the system controller 7.

The above-mentioned threshold value for determining the above-mentioned correlation degree calculation method and whether the image data written in the image memory indicates a color image or a black-and-white image is the image pickup element used in the apparatus. It is appropriately set depending on the number of pixels, the structure of the color filter, the capacity of the image memory and the like.

[0032]

As described above, according to the present invention, it is possible to provide an image signal processing apparatus capable of processing a black and white image signal without deterioration and outputting it.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of an image signal processing apparatus as an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of a monochrome image processing circuit in FIG.

FIG. 3 is a diagram showing an example of an array of color filters arranged on an image pickup surface of an image pickup element in a conventional image signal processing apparatus.

FIG. 4 is a diagram showing a schematic configuration of a color image signal processing circuit in a conventional image signal processing device.

FIG. 5 is a diagram showing a schematic configuration of an image signal processing device as another embodiment of the present invention.

[Explanation of symbols]

 4 Sample / Hold Circuit 5 A / D Converter 7 System Controller 5 Operation Unit 11 Changeover Switch 12 Color Image Signal Processing Circuit 13 Monochrome Image Signal Processing Circuit 14 Changeover Switch 15 D / A Converter 16 Image Data Discrimination Circuit 21 White Balance Circuit 22 Gamma correction circuit

Claims (3)

[Claims] 1. An image signal output means for outputting an image signal having second and third color component signals having a small amount of information with respect to a first color component signal corresponding to a predetermined color component, and the image signal output means. A color image signal processing means for performing color image signal processing on the image signal output from the image signal, and a color image for performing monochrome image signal processing on the image signal output from the image signal output means. Signal processing means and either the color image signal processing means or the monochrome image signal processing means are selected, and the image signal output from the image signal output means is processed by the selected image signal processing means. An image signal processing device, comprising: 2. A color filter having second and third color filter portions having a small occupied area with respect to a first color filter portion corresponding to a predetermined color component is provided, and an image signal is output by imaging a subject. An image pickup means; a color image signal processing means for performing color image signal processing on the image signal output from the image pickup means; and a monochrome image signal processing on the image signal output from the image pickup means. An image output from the image pickup means by selecting one of the color image signal processing means for performing the color image signal processing means and the color image signal processing means or the monochrome image signal processing means. An image signal processing device, comprising: an image signal processing selection means for processing a signal. 3. An image signal output means for outputting a color image signal or a monochrome image signal having second and third color component signals having a small amount of information with respect to the first color component signal corresponding to a predetermined color component. A color image signal processing means for performing color image signal processing on the image signal output from the image signal output means; and a monochrome image signal processing on the image signal output from the image signal output means. A color image signal processing means for determining the image signal, an image signal determination means for determining whether the image signal output from the image signal output means is the color image signal or the monochrome image signal, and the determination result in the image signal determination means. Accordingly, either one of the color image signal processing means or the monochrome image signal processing means is selected, and the image signal output means is selected by the selected image signal processing means. An image signal processing apparatus characterized by comprising an image signal processing selection means for processing the image signal output Ri.