KR20120069551A - Apparatus and method for processing image - Google Patents

Abstract

PURPOSE: An image processing apparatus and an image processing method are provided to reduce bandwidth of a memory by configuration of an image processing unit and to processes an image at high speed. CONSTITUTION: An image processing unit(52) processes an image. The image processing unit outputs a line after image process. An image converting unit(56) inputs a line after image process. The image converting unit outputs a line after performing copy or enlargement of the line. An output timing controlling unit(57) controls timing for outputting a line from the image processing unit.

Description

Image processing apparatus and image processing method {APPARATUS AND METHOD FOR PROCESSING IMAGE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus and an image processing method which can prevent the field of view from being lowered due to the reduction of pixels by a ring pixel when performing image processing.

Background Art [0002] Conventionally, in an imaging device such as a digital camera, an image such as conversion to YUV data, noise reduction, or edge enhancement is performed on bayer data (original image data) inserted from an imaging device when an image is generated. Image processing such as correction and various image conversion such as enlargement, reduction and copying are performed.

When performing the image processing as described above, the original image data is input to the image processing section sequentially for each line in order from the top to the bottom to perform the processing. When performing such image processing, one may be configured to generate a new pixel with reference to a plurality of pixels. In that case, if image processing is performed without taking any countermeasure to the original image data, the left side of FIG. As described above, image data is obtained after processing in a state of being smaller by the periphery of the original image data called ring pixels. In order to prevent the output image after image processing from being reduced and the field of view of the input image in this manner, as shown by the dotted line in the right drawing of FIG. Before the image processing, a ring pixel frame which is a pixel added to the periphery is provided.

In addition to image processing for outputting output image data having the same number of pixels with respect to such input image data, for example, an image conversion such as pixel copy, which enlarges an input image twice, may be performed after image processing. The configuration in the case where such image processing and image conversion are performed continuously can be considered as shown in FIG. That is, the original image data is stored in the SDRAM 4A, and an input DMA (Direct Memory Access) 51A (hereinafter referred to as a readout unit) for reading out the original image data from the SDRAM 4A for each line, and The first filter 53A, the second filter 54A, and the third filter 55A, which are directly connected to each other to perform various image processing on the lines read by the reading unit 51A, output the lines after the image processing. The image processing unit 52A, the image conversion unit 56A (Resize) which is provided in direct connection with the image processing unit 52A, and enlarges or copies the lines after the image processing, and enlarges or copies the lines. The output DMA 58A which is an output part stored in 4A) is provided.

In this case, when the image conversion unit 56A enlarges a line, for example, when two lines are output for one line or the like, the image conversion unit 56A has a longer time to output than the input and store it in the SDRAM 4A. It takes longer. If a new line input is performed during the output by the image conversion unit 56A, normal operation cannot be performed. Therefore, timing is performed so that a line necessary for the next operation is input to the image conversion unit 56A after the output is completed. The request (Request) signal to request is input into the said reading part 51A. In response to the request signal, when the reading unit 51A reads out a new line, the line is input to the first filter 53A, which in turn is input to the second filter 54A and the third filter 55A. After the image processing is performed, a new line is input to the image conversion section 56A.

However, in such a configuration, data cannot be ejected to the lower ring line of the ring pixel frame shown in FIG. Specifically, when the reading unit 51A reads the lower line of the original image data, since the data of the lower ring line is not stored in the SDRAM 4A, even if there is a request in the reading unit 51A. Can't cope Therefore, the ejection operation corresponding to the lower ring line cannot be continued. However, in order to prevent such a problem from occurring, if the configuration of directly connecting the image conversion unit 56A to the image processing unit 52A is stopped, the bandwidth of the SDRAM cannot be reduced and the operation related to image processing is performed. It is difficult to achieve high speed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and the structure in which the image converting portion is directly connected to the image processing portion reduces the bandwidth of the memory, enables high-speed image processing, and reduces the number of ring pixels. Provided are an image processing apparatus and an image processing method which can prevent a decrease in a field of view caused by the above.

In order to achieve the above, the image processing apparatus of the present invention includes an original image data storage unit for storing original image data, a reading unit for reading out and outputting the original image data for at least one line, and the line is inputted. The image processing unit adds a ring pixel according to image processing for each input line and then outputs the line after the image processing, and when the line after the image processing is input, the image processing unit enlarges or resizes the line after the image processing. And an output timing controller for controlling the timing at which the line is output at the reader and the timing at which the line is output after the image processing at the image processor.

In addition, the image processing method of the present invention includes an original image data storing process for storing original image data, a reading process for reading and outputting the original image data for each of one or more lines, and an image for each input line when the line is input. An image processing step of adding the ring pixel according to the processing and outputting a line after the image processing, a line after the image processing is input, and a line which is enlarged or copied to the line after the image processing And an output timing control process of controlling the timing of outputting the line or the timing of outputting the line after the image processing.

 As described above, according to the image processing apparatus and the image processing method of the present invention, high-speed image processing is enabled, and at the same time, a decrease in the field of view due to the reduction of the ring pixels can be prevented.

1 is a block diagram showing the overall configuration of a digital camera equipped with an image processing apparatus according to an embodiment of the present invention;
2 is a schematic functional block diagram showing an image processing apparatus according to an embodiment of the present invention;
3 is a timing chart showing timing of various image processing according to an embodiment of the present invention;
4 is a schematic diagram showing a decrease in field of view due to the reduction of a conventional ring pixel;
5 is a schematic diagram showing an example of an image processing step in the case where a conventional ring pixel frame is provided on an original image;
FIG. 6 is a schematic diagram for explaining a problem occurring in the embodiment of FIG. 5. FIG.

 Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Hereinafter, the image processing apparatus 200 of FIG. 2 will be described in accordance with an embodiment of the present invention. The image processing apparatus 200 is mounted on the digital camera 100 of FIG. 1, for example, various image processing and enlargement, copying, etc., when the Bayer data generated by the imaging device is converted into YUV data. Is configured to perform image conversion processing.

In the digital camera 100, as shown in FIG. 1, the subject is imaged on the CCD 2 through the lens 1, and the image is an analog front end portion (AFE) as an electrical signal. Is sent to (3). In the analog front end section 3, the signal is first amplified by the automatic gain control section (AGC) 31 and converted into a digital signal by the AD converter 32.

An image (bayer data) converted into a digital signal is stored in a memory such as the SDRAM 4 or the like.

The image of the Bayer data stored in the memory is converted into a YUV image by the image processor 5, and then sent to the image compression unit 6 in order, for example, encoded by the image compression unit 6 in JPEG format. . The encoded compressed image is stored in the memory card 7.

Each of the illustrated components cooperates to perform a function as the image processing apparatus 200. The image processor 5 corresponds to the image processor 52 and the image converter 56 of FIG. 2. It demonstrates in detail below.

As shown in Fig. 2, the image processing apparatus 200 includes an SDRAM 4 (hereinafter, referred to as an original image data storage unit), an input DMA 51, an image processing unit 52, and an image conversion unit. (56), it is configured to exhibit functions as a request control 57 (hereinafter, referred to as an output timing controller) and an output DMA 58 as an output timing controller.

The original image data is stored in the original image data storage section 4. Specifically, the analog front end section 3 converts the image signal of the subject converted from the CCD 2 into a digital signal. Bayer data, which is an image, is stored in the original image data storage section 4, which is the memory.

The input DMA 51 corresponds to a reading unit, and accesses the original image data storage unit 4 without using a microprocessor unit (MPU) to describe the original image data. Type in The input DMA 51 is configured to read original image data for one line or a plurality of lines from the upper end to the lower end when the request is received from the output timing control unit 57, and output it to the image processing unit 52. have.

The image processing unit 52 performs various image processing on the lines read by the input DMA 51, and outputs the lines to the subsequent image conversion unit 56 after the image processing. The image processing unit 52 is composed of three filters. For example, the first filter 53 (filter1) converts Bayer data into YUV data, and the second filter 54 (filter2) The noise reduction and the third filter 55 (filter3) sequentially perform edge correction and the like. The three filters are directly connected in series, and the data output from each filter is directly input to the filter of the next process.

In addition, in each filter, a process of constituting one pixel is performed based on the pixels of a plurality of pixels, and in order to prevent the pixels from decreasing by processing the input image as it is, in each filter, a ring The pixel is added to the input line, and the line of the lower portion of the ring pixel is referred to as the lower ring line in this embodiment. In addition, the number of lines of the lower ring line added in the first filter 53, the second filter 54, and the third filter 55 is referred to as L1, L2, L3. In each filter, a storage area for storing the number of lines required for processing is formed in the original image data storage section 4.

The image converting unit 56 (Resize) is provided to be directly connected to the image processing unit 52. In the embodiment of the present invention, the image converting unit 56 (Resize) is configured to enlarge and output the input line. In other words, the image conversion section 56 outputs two lines for one line input, for example, and the output lines are outputted by the output DMA 58 to the original image data storage section 4. Are preserved in

The output timing controller 57 (Request control) is for observing the number of output lines of the third filter 55 and controlling the timing at which the lines are input to the image converter 56. This is to prevent new input until the output is completed when the image conversion section 56 is to enlarge or copy the line. The output timing control unit 57 is configured to control the timing of when to output a line to each of the filters of the input DMA 51 and the image processing unit 52.

As a specific operation of the output timing controller 57, the output timing controller 57 adjusts the output timing of the read unit until all the lines of the original image data are read by the read unit corresponding to the input DMA. The control unit is configured to control the output timing of the image processing unit 52 after all lines of the original image data have been read by the reading unit.

More specifically, the output timing control section 57 does not perform any control when the image conversion section 56 outputs a reduction process, that is, the number of lines smaller than the number of input lines. In this case, since there is no input waiting to the image converting section 56, the input lines can be input continuously, and each block of the filter detects that the input line is missing and replaces each lower ring line with the next filter or image converting section ( 56). That is, in the case of the first filter 53, the lower ring line for L1 is sequentially input to the next second filter 54.

When the image conversion section 56 performs enlargement processing or copying, that is, when more than one line output is performed for one line input, the output timing control section 57 sends the original image data storage section 4 to the original image data storage section 4. While all the lines of the stored original image data are outputted, reading of the lines of the input DMA 51 and output timing thereof are controlled. Specifically, upon detecting that the output is completed by the image conversion section 56, a request is made to the input DMA 51 to read the next line.

Then, the first filter 53, the second filter 54, and the third filter 55, so that each lower ring line is inputted to the image conversion unit 56, in accordance with the ring pixel frame added in each filter. Is configured to make a request for outputting each of the lower ring lines in the following order. The order of these requests is determined in the following order. Here, A is the number of input lines which are the number of lines obtained by dividing the original image data, A is the number of output lines output so far from the third filter 55, B is the number of lower ring lines in each filter, and L1 and L2. , L3, when there is an output line number B between A- (L1 + L2 + L3) ≤B <A- (L2 + L3), the lower ring line is moved from top to bottom from the first filter 53. The output timing control section 57, when there are output lines B between A- (L2 + L3) < = B < Requests the lower ring lines to be output in order from above, and finally, if there is an output line number B between A-L3 &lt; B &lt; A, outputs the lower ring lines to the third filter 55 in order from above. Request to do so.

Since the output timing controller 57 operates as described above, a timing chart relating to the input timing and the input / output timing of each filter is shown in FIG. 3.

Thus, according to the image processing apparatus 200 of the embodiment of the present invention, at the same time having a ring pixel frame, the output of each filter process, which is the image processing unit 52, is inputted to the image converting unit 56 where direct magnification processing or the like is performed. Since the image processing is carried out from the original image and then converted into the enlarged image, the band width of the original image data storage unit 4 is reduced without reducing the field of view of the enlarged image. In this way, a process with reduced power consumption can be realized.

As described above, according to the present invention, even after all the lines are read from the original image data storage unit to the original image data by the reading unit, the output of the lines can be requested to the image processing unit. The image conversion section can also output lines for ring pixels added in the processing section. In addition, since the output timing is controlled, even when one or more lines of output are output to one line of input such as enlargement or copying, it is possible to prevent a situation in which a new input occurs during the output and normal operation cannot be performed. In addition, since the image conversion section is connected directly in series with the image processing section, the processing result in the image processing section is first stored in a memory or the like, so that it is not necessary to read out from the memory in order to perform image conversion again. By reducing the band width, the high speed processing can be performed.

In addition to the above, other embodiments will be described. In the above embodiment of the present invention, image processing by a plurality of filters is performed, but the number of such filters is not limited to the number of filters in FIG. In other words, the image conversion section may be directly connected to the image processing section. In addition, the image processing apparatus of the present invention may be mounted not only in a digital camera but also in a device that requires other image processing. In addition, it goes without saying that various modifications and combinations of the embodiments may be made without departing from the spirit of the present invention.

200 image processing unit
4 original image data storage
51 readers
52 Image Processing Unit
56 Image Converter
57 output timing control

Claims (12)

An original image data storage unit for storing original image data;
A reading unit configured to read and output the original image data for at least one line;
An image processing unit which adds a ring pixel according to image processing for each input line after inputting the line, and performs the image processing, and outputs the line after the image processing;
An image conversion unit for outputting a line which has been enlarged or copied to the line after the image processing when the line after the image processing is input;
And an output timing controller for controlling the timing at which the line is output at the reader or the timing at which the line is output after the image processing at the image processing unit.
The method of claim 1, wherein the output timing control unit,
The output timing of the reading unit is controlled until all lines of the original image data are read by the reading unit,
And after all lines of the original image data are read by the reading unit, controlling the output timing of the image processing unit.
The method of claim 2, wherein the output timing control unit,
And if the image conversion unit detects that the output is completed as all lines of the original image data are read by the reading unit, requesting the reading unit to read the next line.
The method of claim 1, wherein the reading unit,
Image processing, characterized in that the DMA (Direct Memory Access) reads out the original image data stored in the original image data storage unit for one line or a plurality of lines when the request is received from the output timing control unit and outputs the image data to the image processing unit. Device.
The method of claim 1, wherein the image conversion unit,
And an image processor directly connected in series with the image processor.
The method of claim 1, wherein the image processing unit,
And at least one filter.
The method of claim 6, wherein the output timing control unit,
The number of input lines obtained by dividing the original image data, the number of output lines output from the at least one filter, and the number of lower ring lines which are lines of the lower portion of the ring pixel in each of the at least one filter are used. And the timing is determined.
An original image data storing process for storing original image data;
A reading process of reading and outputting the original image data for at least one line;
An image processing step of adding the ring pixel according to image processing for each input line after the line is input, performing the image processing, and outputting the line after the image processing;
An image conversion process of inputting a line after the image processing to output a line which has been enlarged or copied to the line after the image processing;
And an output timing control step of controlling the timing at which the line is output at the time of reading or the timing at which the line is output after the image processing.
The method of claim 8, wherein the output timing control process,
Controlling the timing at which the lines are output at the time of reading until all the lines of the original image data are read;
And after all the lines of the original image data are read out, controlling the timing at which the lines are output after the image processing.
The method of claim 9, wherein the controlling of the timing at which the line is output when the read is performed comprises:
And requesting to read the next line upon the reading, upon detecting that the output of the line which has been enlarged or copied to the line after the image processing is completed.
The method of claim 8, wherein the image processing process,
And outputting a line after the image processing by using at least one filter.
The method of claim 11, wherein the output timing control process comprises:
The number of input lines obtained by dividing the original image data, the number of output lines output from the at least one filter, and the number of lower ring lines which are lines of the lower portion of the ring pixel in each of the at least one filter are used. And determining timing.

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