KR100303493B1 - Pixel Leakage Correction Method of Digital Optical Equipment - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to correcting pixel missing in digital optics, and more particularly, to a method of correcting pixel missing in a digital optical device (CCD; charge coupled device) in a digital camera.

In the conventional digital camera, after the manufacturing process is completed, a test process for retrieving and storing pixel missing positions for each product is required, and an adjustment time for finding and storing a pixel missing position due to occurrence of pixel missing is long. The adjustment method is complicated. In addition, since the digital signal processing IC requires a temporary storage memory for retrieving the pixel missing position and an inactive memory for storing the retrieved pixel missing address, economic efficiency of the entire product is reduced.

According to the present invention, there is provided a selection switch means for retrieving and storing a pixel missing position, and the memory means for retrieving the information of the pixel missing position by a CCD and storing the compressed video signal according to whether the selected selection switch means is configured. It is to be stored directly in a predetermined area, and then to correct the image signal input through the CCD using the pixel missing position information stored in the memory means.

Description

Pixel missing correction method of digital optics

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to correcting pixel missing in digital optics, and more particularly, to a method of correcting pixel missing in a digital optical device (CCD; charge coupled device) in a digital camera.

With the development of digital signal processing technology, technologies in various fields such as video media and video communication, which are applied to such technology, are being developed. In recent years, the image taken by a camera is integrated into a file by combining digital technology with optical technology. Video communication devices that can store and transfer stored files to devices in other places are rapidly developing.

In a digital camera having such a function, a CCD is used to convert incident light into an electrical signal.

Cameras using a CCD as described above have been used in many fields such as a camcorder, a surveillance camera.

However, due to the technical problem of the CCD, there are still missing pixels at a certain position by the CCD. As a result, as shown in FIG. Will appear.

In the present invention, it is possible to correct such a missing pixel,

In the related art, after the manufacturing process of the device is completed, a test step is performed to determine the location of the pixel leakage of the CCD for each product, and the location of missing pixels is stored and the image is input in real time using the stored information. By performing correction for the pixel missing position with respect to

1 illustrates a configuration of a conventional device for correcting pixel missing, wherein light incident through the lens 1a is converted into an electrical image signal through the CCD 1.

The image signal converted as described above is transferred to the digital signal processor (DSP) through the CCD driving and the signal input unit 2, and the digital signal processor 3 is controlled by the microcomputer 4. The digital signal is processed and displayed as an image on display means such as storage or monitor 5.

In a digital optical device having such a configuration, a conventional pixel missing correction process will be described as follows.

When the product process is completed with the configuration as described above, the pixel missing adjustment jig (6) is connected to determine the position of the pixel missing, and to proceed with the test process for storing the identified pixel missing position.

And a black cap is put on the lens 1a part.

Subsequently, when the pixel missing correction command control signal is applied to the microcomputer 4 through the pixel missing adjusting jig 6, the microcomputer 4 controls the digital signal processor 3 to search for the pixel missing position. do.

As described above, since the lens 1a is blocked from the outside, the level of the video signal input through the CCD 1 has a low level as a whole.

By using this, the digital signal processing unit 3 compares the signal levels with respect to the entire address, and finds the pixel missing address.

The digital signal processor 3 stores the retrieved pixel missing address in its own memory area.

When the pixel missing position is found and the storage is completed as described above, the microcomputer 4 notifies the pixel missing adjustment jig 6 that the pixel missing position storage is completed, and completes all processes.

After the pixel missing address stored in the digital signal processing unit 3 by this process, when the user uses the device, it is used as pixel missing correction data,

When a user takes a picture and inputs an electric video signal through the CCD 1 to the digital signal processor 3, the digital signal processor 3 performs digital signal processing on the video signal input in real time, and stores it in the memory. When the pixel missing address is reached, the video signal of the pixel missing address is compensated with the data of the video signal inputted to the previous address of the pixel missing address.

That is, the video signal of the previous address of the pixel missing address is read as it is to be compensated for.

As described above, in the conventional digital camera, after the manufacturing process is completed, a test process for searching and storing the pixel missing positions for each product is required. An adjustment time for finding and storing the pixel missing positions due to the occurrence of pixel missing is required. Long and complicated to adjust.

In addition, since the digital signal processing IC requires a temporary storage memory for retrieving the pixel missing position and an inactive memory for storing the retrieved pixel missing address, economic efficiency of the entire product is reduced.

In order to solve this problem, the present invention provides a selection switch means for retrieving and storing the pixel missing position, and stores the image signal by retrieving the information of the pixel missing position by the CCD according to whether the selected selection switch means is configured. By directly storing in the memory means for using, the correction of the pixel missing can be made simply by using the information stored in the memory means.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing the configuration of digital optics for explaining a conventional pixel missing correction method.

2 is a diagram showing a state displayed on a monitor according to a pixel missing position generated by a CCD;

3 is a block diagram showing the configuration of digital optics according to the pixel missing correction method of the present invention.

4 is a flowchart showing a procedure of performing pixel missing position detection and storage in the pixel missing correction method of the present invention.

Fig. 5 is a flowchart showing an execution procedure of a pixel missing correction process in the pixel missing correction method of the present invention digital optics.

6 is a waveform diagram showing a pixel missing correction time in the present invention, (a) shows a CCD output time waveform, and (b) shows a waveform showing an image output time.

Fig. 7 shows the pixel missing correction time of the prior art and the present invention, (a) is conventional and (b) is the present invention.

The pixel missing correction method of the digital optical device of the present invention,

Setting to low light so as to improve the accuracy of level comparison when detecting the missing pixel position, minimizing light charged to the semiconductor optical element according to the selection of the switch means for executing the pixel missing position detection; Capturing one screen of the video signal input through the storage and storing it in the first storage means, and whether the pixel is missing compared to the reference level set for the entire position of the video signal stored in the first storage means A pixel missing position detection storage step having an execution procedure of the step of discriminating and determining the position information of which pixel missing is determined in a second memory means for compressing and storing an image input through the semiconductor optical device;

In using the device, capturing and temporarily storing a video signal input in real time through a CCD, and reading the pixel missing position information stored in the pixel missing position detection storage process from a second memory means. And a pixel missing correction process including correcting the image information of the corresponding position as the image signal data of the adjacent position.

In the present invention having the execution procedure as described above, the configuration and operation will be described with reference to the embodiment having the configuration according to the present invention shown in FIG.

The CCD 11 drives the CCD 11 to convert the light input from the outside through the lens 11a into an electrical video signal, and outputs the electrical signal. The digital signal is converted into a digital signal. A digital signal processor 13 for receiving the image signal inputted through the CCD 11 and performing a digital signal processing process for displaying and storing the image; The memory unit (DRAM) 14 which is the primary temporary storage means of the image signal processed by the signal processor 13 and the image signal processed by the digital signal processor 13 are temporarily stored in the memory unit 14, The memory control unit 15 outputs the image signal stored in the memory unit 14 to the monitor 16 through the digital signal processing unit 13 according to the vertical synchronization signal of the monitor 16, and is input through the CCD 11. A memory unit 17 storing image signals and storing pixel missing position information, and pixel missing positions The microcomputer 18 controls the execution of the correction of the missing pixel according to the control of each unit for retrieval and storage of information and the pixel missing position information stored in the memory unit 17, and the pixel missing position information of the microcomputer 18. And a switch unit 19 for selecting execution of a retrieval and storage process.

In the embodiment of the present invention having such a configuration, the position of the pixel missing caused by the CCD 11 can be detected through the simple operation of the switch unit 19 without the jig connection as the product itself in which the manufacturing process is completed. And storing the detected position information of the missing pixel at a predetermined position of the memory unit 17 configured to store the input video signal.

In the digital camera having the above-described configuration, the electrical image signal converted and outputted from the CCD 11 is input to the digital signal processor 13 through the CCD driver 12, and the image signal is input to the memory controller 15. Is temporarily stored in the memory unit 14.

When the video signal of the next frame is input, the memory controller 15 divides the video signal stored in the memory 14 into an even / odd field to separate the digital signal processor 13. The monitor 16 outputs to the monitor 16 to display the screen.

While displaying the screen as described above, the memory controller 15 receives the image signal input through the CCD 11 from the digital signal processor 13 and compresses and stores the image signal in the memory 17.

The pixel missing position detection and storage in the digital camera having such a signal processing flow will be described with reference to the embodiment shown in FIG. 4 as follows.

The illuminance is lowered to have a level for detecting the pixel missing position, thereby setting an environment of low illumination.

In this case, the low illumination setting is set to a level that can be determined as missing pixel data.

Thereafter, when the switch unit 19 is turned on, the pixel missing position detection and storage process is performed.

The microcomputer 18 closes the electronic iris to minimize the amount of light charged in the CCD 11, and then captures and stores an image input through the CCD 11 in the memory unit 14.

At this time, the image signal stored in the memory unit 14 has a low value as a low illuminance value, but shows a high value at the pixel missing position.

Therefore, the microcomputer 18 compares the video signal level of each address of the memory unit 14 with a predetermined setting level as a reference level to determine whether or not the pixel is missing.

If an image signal having a value larger than the reference level is found, the corresponding address of the memory unit 14 in which the image signal is recorded is stored in the memory unit 17 as pixel missing position information.

Subsequently, when the comparison with the reference level is completed for the entire address of the memory unit 14, the automatic adjustment process having the steps of pixel missing detection and storage is completed.

Since the omission of pixels generated by the CCD 11 is caused by technical problems of the CCD 11, the position of pixel omission is not changed. Therefore, the above-described process is performed only once after the process of the product is completed. Just run it.

Referring to FIG. 5, a process of performing pixel correction by storing a pixel missing position in the memory unit 17 through the above process will be described below.

The video signal input to the digital signal processor 13 through the CCD 11 is captured by the memory controller 15 and stored in the memory 14.

Thereafter, the microcomputer 18 reads the pixel missing position information stored in the memory unit 17 and corrects the video signal of the corresponding address of the memory unit 14.

FIG. 6 is a waveform diagram illustrating timing for pixel missing address correction, wherein a vertical VGA pulse having a period of 1/30 ms as a reference for driving the CCD 11 as shown in (a), As shown in (b), in the vertical synchronization signal (Vsync) for video signal output,

The first image F1 is captured in the X section and stored in the memory unit 14, and the captured image is corrected in the Y section.

Then, in the Z section, the first image F1 is output to the monitor 16 while the second image F2 is stored in the memory unit 14.

Further, correction of the second image F2 is made in the next W section.

That is, in the vertical retrace periods Y and W in which there is no image, a missing pixel is corrected.

In this case, the correction data is corrected by obtaining data averages of adjacent positions of the missing pixels, and can be corrected only by data of the previous or next position of the missing pixels, and may vary depending on the hardware and software applied. Implementation is applicable.

That is, in the related art, as shown in FIG. 7A, correction is immediately performed at a pixel missing position of an image input in real time. However, in the present invention, one frame is temporarily stored in the memory unit 14 and then temporarily stored. Since the delayed image is displayed, as shown in (b) in which the image signal is not displayed in order to avoid collisions between the image signals, correction of pixel missing in the vertical retrace section is performed.

In addition, although the pixel missing correction section is set in the vertical blanking section, the pixel missing correction is possible in the horizontal blanking section using the horizontal synchronization signal.

Applying the present invention as described above, it is possible to simply solve the pixel omission caused by the technical limitations of the CCD, and to reduce the burden of the conventional digital signal processing IC, it is possible to improve the economics of the device.

Claims (2)

(Once correcting) a pixel missing position detection storing process of detecting and storing a pixel missing position of a CCD; and when the user uses a digital optical device, the pixel missing position detection storing process of the image signal data input to the CCD The pixel missing correction process is performed to correct from the stored information, and the pixel missing position detection storage process is performed by setting a low illumination environment for detecting a pixel missing position, and selecting a switch means for executing the pixel missing position detection. Therefore, minimizing the light charged in the semiconductor optical device, capturing one screen of the image signal input through the CCD and storing it in the first storage means, and the image signal stored in the first storage means Determining whether or not a pixel is missing by comparing with the reference level set for the entire position, and position information in which the missing pixel is determined And a step of storing the image input through the semiconductor optical device in a second memory means for compressing and storing the image. The pixel missing correction process performed by the user in using the device is input in real time through the CCD. Capturing and temporarily storing a video signal, and reading the pixel missing position information stored in the pixel missing position detection storing process from a second memory means, and storing the video information of the corresponding position of the temporarily stored video signal at the adjacent position. The pixel missing correction method of the digital optical device, characterized in that the step of correcting as. The pixel missing correction method of claim 1, wherein the pixel missing correction is performed in the retrace period of the vertical synchronization signal or the horizontal synchronization signal.