JPH08163445A - Still image data generator - Google Patents

Abstract

PURPOSE: To generate improve image data in which defective data are reduced less than image data obtained from each of image pickup elements by synthesizing image data from an image pickup element having a defective pixel. CONSTITUTION: A video camera 10 has 1st and 2nd CCD image pickup elements 16, 18 of identical configuration and a half mirror 14 delivering an incident optical image to the 1st and 2nd CCD image pickup elements 16, 18. First and second image memories 28, 30 store an image signal of the same incident optical image respectively from the 1st and 2nd CCD image pickup elements 16, 18. An image processing unit 32 checks a state of a pixel of the 2nd CCD image pickup element 18 on the position corresponding to a defective pixel of the 1st CCD image pickup element 16 based on defective pixel position data of the 1st and 2nd CCD image pickup elements 16, 18 and generates image data obtained by replacing a content of a storage cell of the 1st image memory 28 corresponding to the defective pixel of the 1st CCD image pickup element 16 with a content of a storage cell of the 2nd image memory 30 corresponding to the defective pixel when there is no defect in the pixel of the 2nd CCD image pickup element 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a still image data generator using a CCD (charge coupled device) image pickup device.

[0002]

2. Description of the Related Art CCD image sensors are widely used in ordinary video cameras. For example, in a frame interline CCD image pickup device mainly used in fields requiring high image quality such as broadcasting, each pixel arranged in a matrix of the image pickup unit converts an incident light image into an electric charge 1. It consists of one photodiode, one CCD element for forming a vertical CCD shift register that performs charge transfer operation with a plurality of photodiodes, and a transfer gate that controls the transfer of signals between them. The signal charge accumulated in the photodiode is read out to the vertical CCD shift register during the vertical blanking period. After that, by applying a high-speed vertical transfer pulse, the signal charge is transferred to the storage section of the CCD image pickup device through the vertical CCD shift register and then to the horizontal CC.
It reaches the D shift register and is then output through the horizontal CCD register.

Since defective pixels are generated in the CCD image pickup device due to various causes in the manufacturing process, it is necessary to inspect whether the defective state is within the standard as a product. Standards for this inspection include a point defect standard, a line defect standard, and a spot / uneven zone standard. For example, in the inspection of the point defect standard, CC when the device is in the light-shielded state
Pixels that generate a local peak point that exceeds the predetermined range of the output waveform of the D output, that is, a dark signal white point, and pixels that generate a local dip point that exceeds the predetermined range when the element output state is saturated, that is, an OF black point Etc. are counted and it is checked whether the total number is within a specific ratio to the total number of pixels.
In the line defect standard inspection, it is checked whether the output signal level of the entire CCD line satisfies a predetermined range. In the spot / uneven zone standard, the ratio of the local unevenness of the output signal to the overall average amplitude is determined. Find out.

[0004]

When such an inspection is carried out, a high-resolution CCD image pickup device that passes all inspection standards has a yield of about 10% at best.
Most CCD imagers are rendered unusable. But,
If the CCD image sensor is used for still images only, CC
D Even if the pixel data obtained by the image pickup device is taken into an image memory having a pixel and a one-to-one storage cell and the data from the defective pixel is interpolated with the data from the surrounding normal pixels, it can be used even if the standard is not satisfied. It will be possible. However, the resolution of the interpolated portion is lower than usual, and the interpolated data does not become satisfactory data in the portion where defective pixels are concentrated,
The CCD image sensor cannot be used even for a still image only.

Therefore, an object of the present invention is to provide a still image data generating apparatus which uses a CCD image pickup device having defective pixels and generates still image data without lowering the resolution.

[0006]

According to the still image data generating apparatus of the present invention, the same first and second image pickup CCD image pickup devices and the first and second incident light images are provided in the video camera.
It includes a half mirror that transmits to the CCD image sensor. The image memory means has first and second memory areas for storing image signals of the same incident light image from the first and second CCD image pickup devices, respectively. The image processor checks the state of the pixel of the second image sensor at the position corresponding to the defective pixel of the first CCD image sensor based on the defective pixel position data of the first and second CCD image sensors, and determines the pixel state in the second image sensor. If there is no defect in the
Image data is generated by replacing the content of the memory cell in the first memory area corresponding to the defective pixel of the CCD image sensor with the content of the corresponding memory cell in the second memory area. Like this
By combining the image data from the CCD image pickup devices 16 and 18 having a pixel defect, it is possible to generate improved image data in which the defect data is smaller than the image data obtained from each.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 is a block diagram showing a still image data generating apparatus of the present invention. An optical image of an object to be photographed is incident on the video camera 10 via the lens 12. In the video camera 10, the incident light is 45 ° with respect to the axis of the lens 12.
Reach the half mirror 14 that is arranged at an angle of
Half of the amount of light passes through the half mirror 14 and CC
Reaching the D image sensor 16, the other half is the half mirror 1.
It is reflected by 4 and reaches the CCD image pickup device 18. These image pickup devices 16 and 18 are of the same standard, and are assumed to be for monochrome images here for the sake of simplicity. It should be noted that each of the image pickup devices 16 and 18 includes defective pixels at irregular positions due to the manufacturing process.

The image pickup devices 16 and 18 are controlled by the video signal generators 20 and 22 which operate in synchronization with each other to extract output signals and add vertical and horizontal synchronizing signals, for example, as NTSC video signals. The signals are supplied to analog / digital converters (hereinafter referred to as ADCs) 24 and 26, respectively. Each of the ADCs 24 and 26 generates a clock signal based on a synchronizing signal included in the input video signal, and the input video signal is taken in by the clock signal and converted into digital image data.

The image memories 28 and 30, which are frame memories, have a one-to-one correspondence with the pixels of the CCD image pickup devices 16 and 18.
, That is, the same number of memory cells as pixels, and sequentially stores digital image data for each frame sent from the ADCs 24 and 26. Therefore, defective data is stored in the memory cell corresponding to the defective pixel.

The image processor 32 is a central processing unit (CP).
U) and a configuration including a read-only memory (ROM) for storing a program for executing the processing procedure according to the present invention, or an ordinary personal computer. The image processor 32 is supplied with the vertical synchronizing signal extracted from the output signal of the video signal generator 20 by the vertical separation circuit 34. Since the video signal generators 20 and 22 operate in synchronization, the vertical synchronization signal may be taken out from the video signal generator 22. When the operator turns on the switch 36, the image processor 32 supplies a capture stop signal to the ADCs 24 and 26 in response to the vertical sync pulse supplied immediately thereafter. When the ADCs 24 and 26 stop the generation of digital image data in response to the capture stop signal and the switch 36 is turned on in the image memories 28 and 30,
The same image frames taken by the video camera 10 are accumulated.

2A and 2B show 7 × 7 (A1 to G) storage cells of the image memories 28 and 30, respectively, which are smaller than actual storage cells.
FIG. 7 is a diagram schematically showing a memory cell of 7). Image sensor 16
And 18 are assumed to have similar pixels A1 to G7. Defective data is stored in the memory cells of the image memories 28 and 30 corresponding to the defective pixels of the image pickup devices 16 and 18, and a cross mark is attached to the memory cell storing the defective data in the drawing. The image memory 28 includes A1 to A7, C2, and D.
Defective data is stored in memory cells 5, 5, E6 and F2. The image memory 30 has defective data in the storage cells B3, D4, F2, and G6. Since the position data of the defective pixel can be obtained by the defect inspection of the CCD image pickup device as described above, by inputting the defect position data to the image processor 32, the image processor 32 can store the image data in the image memories 28 and 30. It is possible to recognize at which position the defect data is stored. When such data is not available, different subjects for measurement are photographed by the video camera 10, the state of the stored data in the storage cells of the image memories 28 and 30 is checked by the image processor 32, and the CCD image pickup device 16 Defect position data of pixels 18 and 18 may be generated.

The image processor 32 checks the state of the pixel of the image pickup element 18 at the position corresponding to the defective pixel of the element 16 based on the defect position data of the CCD image pickup elements 16 and 18, and the pixel of the image pickup element 18 has a defect. If there is not, the contents of the storage cell of the image memory 28 corresponding to the defective pixel of the image sensor 16 are
It is rewritten with the content of the corresponding storage cell of the image memory 30. That is, A1 that stores the defect data of the image memory 28
Since the data of the storage cells of the image memory 30 corresponding to the storage cells of A7, C2, D5 and E6 is normal, the contents of these storage cells of the image memory 28 are the same as those of the corresponding storage cells of the image memory 30. Can be rewritten with the content. However, since both the image memories 28 and 30 have defective data in the memory cell of F2, the image processor 32 does not rewrite the memory cell for this memory cell. In such a case, the image processor 32 uses the F2 of the image memory 28.
A pixel defect is compensated by obtaining an average value of the storage data of the storage cells F1, E2, F3 and G2 around the memory cell and performing interpolation such as writing in the storage cell of F2. When the positions of the defective pixels of the image pickup devices 16 and 18 coincide with each other,
The number of defective data can be reduced by replacing one with another image sensor.

In this way, by combining the image data from the image pickup devices 16 and 18 having pixel defects,
Improved image data can be generated with less defect data than the image data obtained from each. The image processor 32 reads this image data from the image memory 16 and supplies the data to an output device 38 such as a display or a printer.

FIG. 3 is a block diagram showing a part of another embodiment of the present invention. When the subject is stationary, the video signal generator 20 can be used even if the images are taken before and after in time.
The output signals of 22 and 22 are the same. Video signal generator 2
The output signals of 0 and 22 are selected by the switcher 40 controlled by the image processor 32 and supplied to the ADC 26. The image memory 30 ′ has two memory areas corresponding to the memory capacity of the image memory 30, and stores digital image data regarding the image sensor 16 supplied from the ADC 26 in one memory area to obtain a digital image regarding the image sensor 18. Store data in the other memory area. Hereinafter, by the same operation as described above, image data obtained by improving the image data obtained from each of the image pickup devices is generated in one memory area. In this embodiment, the number of components can be reduced as compared with FIG. However, this configuration cannot be adopted when the subject moves.

[0015]

According to the present invention, by combining the image data from the image pickup devices 16 and 18 having a pixel defect, the improved image data in which the defect data is smaller than the image data obtained from each image is generated. be able to.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a still image data generation device of the present invention.

FIG. 2 is a simplified diagram of an image memory for explaining the operation of the device of the present invention.

FIG. 3 is a block diagram showing a part of another embodiment of the device of the present invention.

[Explanation of symbols]

 14 Half Mirror 16 First CCD Image Sensor 18 Second CCD Image Sensor 28 First Memory Area 30 Second Memory Area 32 Image Processor

Claims (1)

[Claims] 1. A video camera including the same first and second CCD image pickup devices and a half mirror for transmitting an incident light image to the first and second CCD image pickup devices, and the first and second CCDs. Image memory means having first and second memory areas for respectively storing image signals of the same incident light image from the image pickup device, and the first CCD image pickup based on defective pixel position data of the first and second CCD image pickup devices. The state of the pixel of the second CCD image pickup element at the position corresponding to the defective pixel of the element is checked. If the second CCD image pickup element has no pixel defect, the first memory area corresponding to the defective pixel of the first CCD image pickup element is checked. Still image data generation, comprising: an image processor that generates image data by replacing the content of a memory cell with the content of the corresponding memory cell of the second memory area. Location.