JP2007281654A - Image reproducing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reproducing apparatus capable of improving the image quality of a reproduced image. <P>SOLUTION: A memory card 1 stores image data and header data which are divided into a plurality of regions and compression-coded at a predetermined compression rate per region. Address data indicating the positions of the divided regions and the compression rate per region are recorded in the header data. A filter 5 smoothes a boundary between a first region and a second region, adjacent to the first region from among a plurality of regions within decompressed image data, on the basis of the header information that indicates the position of each region and the compression rate. A calculation section 7 sets the smoothing processing range, where smoothing is to be executed on the filter 5 on the basis of the header data. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image reproducing apparatus that reproduces image data, and more specifically to an image reproducing apparatus that decompresses compressed image data that has been compression-encoded in an imaging process and reproduces the decompressed image data.

  Many methods have been developed for digitizing a captured image and then compressing and recording it. When compressing and encoding a captured image, there is a method of selecting an area where a large amount of information desired by the user exists and compressing it while leaving as much information as possible. For example, Patent Document 1 discloses a method of encoding a captured image using a different compression ratio between the focused area and the out-of-focus area by dividing the captured image into a focused area and a non-focused area of the subject. Has been.

In addition, as shown in Patent Document 2, some of the image pickup devices include a fixed focal length image input optical system having a function of optically compressing a peripheral portion of an input image, and the input optical system. There has also been proposed an apparatus that captures an image from which distortion is removed by correcting and converting a received light image including distortion due to compression of an input optical system.
JP 2000-209590 A JP-A-10-233950

  However, Patent Document 1 does not describe a case where data that has been irreversibly compressed and encoded is decompressed and reproduced and displayed. In an image compressed and encoded by the method described in Patent Document 1, images having different compression rates exist in one image. In image data with different compression ratios, the amount of high-frequency components included is different, resulting in a difference in image quality after decompression and a step (discontinuity) due to the difference in image quality at the boundary of the reproduced image. .

  An object of the present invention is to provide an image reproducing apparatus capable of improving the quality of a reproduced image even when one image is composed of a plurality of compressed image data having different compression rates. To do.

  The present invention has been made to solve the above-described problem. Image data output from an image sensor that receives an optical image from an optical system is divided into a plurality of regions, and each region has a predetermined compression rate. An image reproducing device that decompresses compressed image data having header information indicating the position and compression ratio of each region, and reproduces the decompressed image data. Filtering means for smoothing a boundary between a first area of the plurality of areas in the decompressed image data and a second area adjacent to the first area, and the smoothing based on the header information And a setting means for setting a smoothing processing range for executing the filter means to the filter means.

  In the image reproducing device of the present invention, the filter means may extend the decompressed image data within the smoothing range across both the low compression ratio area and the high compression ratio area across the boundary. Smoothing is performed.

  In the image reproducing device of the present invention, the filter means smoothes only the decompressed image data within the smoothing range in the high compression area based on the decompressed image data in the low compression ratio area. It is characterized by that.

  Further, in the image reproducing device of the present invention, the filter means sandwiches the boundary, the average value of the expanded image data in the region with the low compression ratio, and the average value of the expanded image data in the region with the high compression ratio A difference from the value is obtained as a step amount, and based on the step amount, the expanded image data within the smoothing range is processed according to the position of the expanded image data to be processed.

  In the image reproducing apparatus of the present invention, the optical system is a distorted optical system that condenses optically by compressing a peripheral portion with respect to a central portion, and the header information is optical characteristic information of the distorted optical system. The filter means corrects optical characteristics of the expanded image data within the smoothing processing range based on the header information including the optical characteristics information, and executes the smoothing. And

  According to the present invention, image data output from an image sensor that receives a light image from a distortion optical system that optically compresses and collects a peripheral portion with respect to a central portion is used as an optical characteristic of the distortion optical system. Accordingly, the compressed image data is generated by dividing into a plurality of preset areas and compression-coding at a predetermined compression rate for each area, and decompressing the compressed image data having header information indicating the optical characteristics, And a boundary between a first region and a second region adjacent to the first region among the plurality of regions in the decompressed image data based on the header information. An image reproducing apparatus comprising: a smoothing filter means; and a setting means for setting a smoothing processing range for performing the smoothing in the filter means based on the header information.

  According to the present invention, the smoothing range is determined based on the header information indicating the position of each area and the compression rate, and the smoothing process is performed. Therefore, the boundary portion discontinuity caused by the difference in the compression rate in the decompressed image data is performed. The effect of eliminating the (step) and improving the quality of the reproduced image can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, a first embodiment of the present invention will be described with reference to FIGS. In the present embodiment, an example is described in which the present invention is applied to an image reproducing apparatus that divides a shooting screen into a plurality of areas at the time of imaging and reproduces image data created by compression encoding at different compression rates for each area. It is carried out. FIG. 1 shows the configuration of the image reproducing apparatus according to the present embodiment. First, the function of each part will be described.

  The memory card 1 is a card-like recording medium that stores image data (including compressed image data after compression) generated by imaging and header data. In the header data, address data indicating the position of the divided area and the compression rate for each area are recorded. The card R / W circuit 2 accesses the memory card 1 and reads and writes image data. The data bus 3 is a transmission path for various data.

  The decompression circuit 4 decompresses the compressed and encoded image data. At the time of decompression, the image data is decompressed at a decompression rate corresponding to the compression rate at the time of compression for each region based on the header data. The filter 5 (filter means) performs a smoothing process for smoothing boundaries between regions having different compression ratios on the decompressed image data. The operation button 6 is a button operated by the user to input various instructions. The arithmetic circuit 7 (setting means) detects the content of the instruction from the user based on the signal output from the operation button 6, and performs a smoothing process based on the header data read from the memory card 1. A range (smoothing process range) is determined. The arithmetic circuit 7 sets the determined correction range in the filter 5.

  The memory 8 is a work memory that temporarily stores data. The TFT control circuit 9 converts the image data into a format suitable for display. The TFT 10 displays an image. The compression circuit 11 compresses and encodes image data with a lossy compression encoding method at different compression rates for each region, and stores the image data in the memory card 1 via the card R / W circuit 2. The header data is generated along with the compression encoding and stored in the memory card 1 in the same manner. The video output circuit 12 generates a video signal during reproduction.

  Next, an outline of the operation of the image reproduction apparatus will be described. The arithmetic circuit 7 detects the instruction content from the operation button 6 and the reproduction process is started. First, image data and header data recorded in the memory card 1 are read out by the card R / W circuit 2 and recorded in the memory 8 via the data bus 3. The image data recorded in the memory 8 is read by the decompression circuit 4, decoded into luminance (Y) data and color (Cr, Cb) data, and recorded in the memory 8.

  The header data recorded in the memory 8 is read out to the arithmetic circuit 7, and the position of the correction range that is the boundary portion of the divided area is determined based on the address data in the header data. When the correction range is determined, the image data in the memory 8 is read into the filter 5 as appropriate, the smoothed image data is replaced with the correction range data, and correction processing is performed. The corrected image data is output to the TFT 10 through the TFT control circuit 9 and an image is displayed on the TFT 10. Further, the image data after the correction process is output as a video signal through the video output circuit 12 or is recorded on the memory card 1 after being compressed by the compression circuit 11 according to the operation content.

  Next, a correction range (smoothing process range) on which smoothing processing is performed in the present embodiment will be described. FIG. 2 shows an example of the positional relationship between the high-compression image area 14 and the low-compression image area 16 in the shooting screen 13. In FIG. 2, there is a low-compression image region 16 in the center portion and a high-compression image region 14 in the peripheral portion, and a boundary 15 is located between them. Since the low-compression image region 16 and the high-compression image region 14 include different frequency components, a step is generated in a straight line along the boundary 15, resulting in an unsightly image. Therefore, in the present embodiment, the step is made inconspicuous by performing smoothing processing along the boundary 15.

  In this description, the case where the smoothing process is performed on the luminance (Y) data is described, but the same process can be performed on the color (Cr, Cb) data as necessary. FIG. 3 shows the correction range 17. The correction range 17 includes a boundary portion between the low-compression image region 16 and the high-compression image region 14 as shown in the figure, and is set so as to extend over both the low-compression image region 16 and the high-compression image region 14.

  Next, the first smoothing method according to the present embodiment will be described with reference to FIGS. Prior to the start of the smoothing process, the image state within the correction range is checked by the arithmetic circuit 7, and if there is discontinuous data such as an edge portion of the subject image in the correction range, that portion is excluded from the correction range. This is in order to prevent the data from being lost in the smoothing process when there is discontinuous data such as edges in the image in the correction range. Note that the above-described investigation and resetting of the correction range are also performed by a second smoothing method described later. In this embodiment, in order to simplify the description, it is assumed that there is no discontinuous image data such as an edge in the correction range.

  FIG. 4 shows the data correction range and the processing range of the filter 5. This figure shows a state when smoothing processing is performed on the data of the pixel D6, and the filter 5 performs smoothing processing using the data of the pixels D3-D9 surrounded by the thick line 101 in the drawing. FIG. 5 shows the configuration of the coefficient register (coefficient register 18 in FIG. 6) in the filter 5, and FIG. 6 shows the configuration of the filter 5a (corresponding to the filter 5 in FIG. 1) corresponding to the first smoothing process. ing.

  In the filter 5a, the image data before smoothing processing from the memory 8 is stored in the input buffer 19 via the data bus 3, and sequentially transferred to the shift register 20. The data stored in the shift register 20 is sequentially transferred pixel by pixel to the next stage, and is added to a product-sum operation circuit including a multiplier array 21, a coefficient register 18, and an adder 22. A part of the coefficient register 18 and a part of the multiplier array 21 are not shown. Since the filtering process in the product-sum operation circuit is known, the description thereof is omitted.

  The filter 5a in this embodiment is set with the coefficients (g-3, g-2, g-1, g0, g1, g2, g3) in the coefficient register 18 so as to have a low-pass filter (LPF) characteristic. In the smoothing process of the data of the pixel D6 in FIG. 4, the data of the pixels D9-D3 are used. The coefficient of the low-pass filter is selected according to the compression ratio of the image in each region, and is set so that the degradation of the image due to the smoothing process is minimized. Since the coefficient setting method of the low-pass filter corresponding to the image quality of the processed image is known, the description thereof is omitted.

  FIG. 7 shows the state of data before the smoothing process, and FIG. 8 shows the state of data after the smoothing process. In this example, the data correction range is a portion including the three pixels on the left and right of the boundary 15 (6 pixels in total), and the data of the pixels D3 to D8 is the correction target. In the case of correction of the data correction range (D3-D8) shown in FIG. 4, the data of the pixels D0-D11 are sequentially read from the memory 8 and processed. For example, when correcting pixel D3, processing is performed using the data of pixels D0-D6, and when correcting pixel D8, processing is performed using the data of pixels D5-D11.

  The processed data is stored in the output buffer 23 in FIG. 6 and is replaced with the data in the correction range in the memory 8. For example, when the coefficients (g-3, g-2, g-1, g0, g1, g2, g3) in the coefficient register 18 are equally 1/7, before the correction shown in FIG. The data is the corrected data shown in FIG. That is, the data (24) of the pixel D6 in FIG. 7 is obtained by the averaging of the data of the pixels D3-D9 and becomes the data (25) of the pixel D6 in FIG. As shown in FIG. 8, the step near the boundary (15) that occurred in FIG. 7 is filled by the smoothing process, and a smooth image is obtained.

  Next, the second smoothing method according to the present embodiment will be described with reference to FIGS. The second smoothing method is a method of correcting data of an image with a high compression ratio and replacing the data with reference to an image with a low compression ratio. The configuration and correction range of the filter used for the smoothing process are the first. This is different from the smoothing method. The correction range and the correction procedure will be described with reference to FIGS.

  FIG. 9 shows a correction range in the second smoothing method. As in the case of FIG. 2, the image data is set such that the compression rate in the central portion is low and the compression rate in the peripheral portion is high. Therefore, as shown in FIG. 9, the peripheral portion in contact with the boundary 15 becomes the correction range 26. As shown in FIG. 10, the correction procedure targets the correction range 28 on the basis of the image in the range (27) in which the value is replaced by the horizontal correction after the horizontal correction. Processing in the vertical direction is performed. By this procedure, the entire periphery of the boundary 15 is processed.

  Specific processing contents will be described with reference to FIGS. In the second smoothing method of the present embodiment, the filter 5b in FIG. 12 (corresponding to the filter 5 in FIG. 1) is used instead of the filter 5a in the first smoothing method of the present embodiment, and the rest is the same. It is. FIG. 11 shows a correction range of data in the second smoothing method and a range of data input to the filter 5b corresponding to the correction range. FIG. 11 shows a state when the data of the pixel D7 is being processed. When processing the data of the pixel D7, the data (D0-D7) surrounded by the thick line 102 in the figure is input to the filter 5b.

  FIG. 12 shows the configuration of the filter 5b. In order to simplify the configuration, the filter 5b has a configuration in which the multiplication circuit suitable for the filter 5a is omitted. In addition, a 1/8 circuit 33 (3-bit shift circuit) for normalizing the addition result is placed after the adder 32. The configuration other than the above is the same as the configuration of the filter 5a shown in FIG.

  As shown in FIG. 11, the smoothing process is started from processing of data (D7) having a high compression rate adjacent to the data boundary. First, in order to process the data (35) of the pixel D7 in FIG. 13, the data of the pixels D0 to D7 are read from the input buffer 30 and set in the shift register 31. Data of each pixel set in the shift register 31 is output to the adder 32 and added. The smoothed data (D7) output from the adder 32 is stored in the output buffer 34 through the 1/8 circuit 33.

  In the next processing of the pixel D8, the data of the pixel D8 is newly added and is simultaneously shifted by one data. Therefore, the processing is started with the data of the pixels D1-D8 set in the shift register 31. The smoothed pixel D8 data output from the 1/8 circuit 33 is also written to the output buffer 34 in the same manner as the pixel D7 data. Since the data within the correction range is processed by the above procedure, the pre-correction data shown in FIG. 13 becomes the post-correction data shown in FIG. 14 after the correction processing. As shown in FIG. 14, data with a high compression rate is corrected based on data with a low compression rate.

  Next, the third smoothing method according to the present embodiment will be described with reference to FIGS. As with the second smoothing method, the third smoothing method is a method of correcting data of an image with a high compression ratio on the basis of an image with a low compression ratio and replacing the data. Performs the smoothing process by measuring the level difference at the boundary and adding (subtracting) the measured level difference in stages. Therefore, unlike the first and second smoothing processing methods, processing for detecting discontinuous data such as an edge portion of a subject image in the correction range and processing for excluding the data from the correction range are not performed. This is because the first and second smoothing methods replace the original data with the smoothed data, whereas the third smoothing method simply adds (subtracts) a smoothing value to the original data. Therefore, even when there is discontinuous data, an unnatural image is not produced.

  In this description, the correction range is described as six pixels with a high compression ratio near the boundary. That is, the correction range is the same as the correction range of the second smoothing method described above. FIG. 15 shows a configuration of a filter 5c (corresponding to the filter 5 in FIG. 1) corresponding to the third smoothing method. FIG. 15 shows a state when data of the pixel D6 is processed.

  As a preparatory stage of the smoothing process, the data of the pixels D6-D11 and the data of the pixels D0-D5 are input to the shift register 38 and the shift register 39, as shown in the figure. The data (D6-D11) of the shift register 38 is added to the adder 40, and the addition result is output to the subtractor 42. Similarly, the data (D0-D5) of the shift register 39 is added to the adder 41, and the addition result is output to the subtractor. From the above processing, the output of the subtractor 42 is the difference between the sum of the image data for six pixels with a high compression ratio near the boundary and the sum of the image data for six pixels with a low compression ratio. That is, the output of the subtracter 42 indicates a value that is six times the average step. The output of the subtracter 42 is stored in the step register 43 and then applied to the multiplier 45.

  Data from the subtraction coefficient setting circuit 44 is added to the other input of the multiplier 45, and step data obtained by multiplying the average step by the output value of the subtraction coefficient setting circuit 44 is input to the subtractor 46. Added. The subtraction coefficient setting circuit 44 sets a value of 3/24, 1/12, or 1/24 according to the pixel position (distance from the boundary) of the data to be corrected. The level difference data added to the subtractor 46 has a value of 3/4, 1/2, or 1/4 of the average level difference. Data (D6) from the shift register 38 is added to another input of the subtractor 46, and the subtraction result is stored in the output buffer 47.

  The details of the smoothing process will be described with reference to FIGS. FIG. 16 shows data before correction. When the data (48) of the pixel D6 in FIG. 16 is processed, the subtraction coefficient setting circuit 44 of FIG. 15 sets 3/24. Therefore, when the data of the pixel D6 is output, it is 3/4 of the average step (ΔY). The value will be subtracted from the original data value of pixel D6. FIG. 17 shows the data after the smoothing process. For the data (49) of the pixel D6 and the data of the pixel D7, the value of 3/4 of the average step (ΔY) is subtracted from the value of the original data. For D8 and D9 data, 1/2 of the average step is subtracted from the original data value, and for pixels D10 and D11, 1/4 of the average step is subtracted from the original data value. The processing result is shown.

  In the above description, the data has been described in units of two (D6, D7, etc.) and the same subtraction coefficient is used. However, smoother image quality is realized by changing the subtraction coefficient for each data. It is also possible. Further, when correcting the data of the pixel D6, the output value of the multiplier 45 is subtracted from the original data of the pixel D6. However, the output value of the subtraction coefficient setting circuit 44 is set to 1/24, The output value of the multiplier 45 may be added to the data D5.

  As described above, according to the present embodiment, header data including the position and compression rate information of each region is generated corresponding to the compressed image data compression-coded at a plurality of different compression rates for each region. In the reproduction of the compressed image data, the position and compression rate information of each area is obtained from the header data, the smoothing range and the smoothing method are determined, and the smoothing process is performed. In this case, the discontinuity (step) in the boundary portion caused by the difference in compression rate is eliminated, and a display image that is easy to view can be created. As a result, the quality of the reproduced image can be improved.

  In addition, according to the first smoothing processing method, when the boundary level difference caused by the difference in compression rate is eliminated, both the low compression rate region and the high compression rate region are processed equally. Thus, smooth image quality without any deviation can be realized. Further, according to the second and third smoothing processing methods, when the step at the boundary portion caused by the difference in compression rate is eliminated, the resolution is low (on the basis of the region with high resolution (low compression rate)) ( Smoothing is performed by changing the data on the side with the higher compression ratio, and the data on the higher resolution side is smoothed without being affected. The effect that the data on the higher side is retained is obtained. In addition, according to the third smoothing method, the smoothing process is performed by increasing / decreasing the data amount with reference to the original data, so that the original data state remains and smoothing is performed. Smoothing processing is performed without impairing the resolution.

  Next, a second embodiment of the present invention will be described with reference to FIGS. In this embodiment, a distortion optical system combining two cylindrical lenses (103, 104) as shown in FIG. 18 is added as an optical system of the imaging apparatus, and the peripheral portion is optically compressed and condensed. This is an example in which the present invention is applied to an imaging apparatus having a distorted lens unit having a condensing characteristic. In the above imaging device, the screen is divided into a plurality of areas at the time of imaging, and the image data is compressed and encoded at different compression rates for each divided area and recorded on the memory card. As shown, the light quantity distribution of the distortion optical system is used.

  19 and 20 show the characteristics of the distorted lens unit. The object screen shown in FIG. 19 divided at equal intervals is projected onto the light receiving surface of the image sensor after passing through the distorted lens unit, as shown in FIG. 20, where the central portion is wide and the peripheral portion is narrow. As a result, the amount of received light is large at the peripheral portion and small at the central portion.

  The state of the amount of received light will be described with reference to FIGS. FIG. 22A shows a light amount distribution on the light receiving surface when uniform light is received, and shows how the amount of received light decreases as it moves from the peripheral part to the central part. FIG. 22A shows a light amount distribution between points A and B on FIG. As shown in FIG. 22A, the amount of received light is small in the central portion and large in the peripheral portion. As is well known, the light amount distribution is determined by the lens design, and various states can be considered. In this example, the light amount ratio between the central portion and the peripheral portion is described as being about twice.

  FIG. 22B shows a state of region division when region division is performed based on the amount of received light. In this example, the screen is divided into two areas based on the amount of received light. FIG. 22B shows an example in which the amount of light is 62.5% (5/8) as a region boundary. Also in this example, as in the first embodiment, a case will be described in which the compression rate of the central portion in compression encoding is low and the compression rate of the peripheral portion is high.

  The boundary position and compression rate information is recorded on the memory card 1 together with the image data as header data, as in the first embodiment, and is expanded on the memory 8 during the reproduction operation. Read and use. In the case of an imaging apparatus in which the boundary position and the compression rate are determined so as to correspond one-to-one with the type of strain optical system to be used, the header data includes only information on the type of optical system. The arithmetic circuit 7 sets a smoothing processing range using information in which the type, the boundary position, and the compression rate are associated in advance.

  Hereinafter, the first smoothing method of the present embodiment will be described. Similar to the second smoothing method of the first embodiment, the first smoothing method is a method of correcting data of an image with a high compression ratio on the basis of an image with a low compression ratio and replacing the data. However, the configuration of the filter 5 used for the smoothing process is different from that of the second smoothing method of the first embodiment.

  In the present embodiment, as described above, an optical system having a non-uniform light amount distribution is used, and the smoothing process is performed in consideration of optical characteristics. Specifically, the light amount distribution is as shown in FIG. 22A, and the correction range is a narrow range when viewed as a whole. Therefore, the change in the light amount is represented by linear approximation on the light amount distribution. Smoothing is performed as a thing. In this smoothing process, the data change due to the optical characteristics is removed from the uncorrected data, and smoothing is performed by applying a low-pass filter to the image with a high compression ratio based on the image with a low compression ratio in that state. Processing is in progress.

  Specific processing contents will be described with reference to FIGS. FIG. 23A shows the configuration of a coefficient register (coefficient register 50 in FIG. 24) for correcting optical characteristics. FIG. 23B shows the configuration of a coefficient register (coefficient register 51 in FIG. 24) for having an LPF characteristic for performing smoothing processing. FIG. 24 shows the configuration of a filter 5d (corresponding to the filter 5 in FIG. 1) that performs smoothing processing. FIG. 24 shows a state when the data of the pixel D6 shown in FIG. 25 is being corrected.

  In the filter 5d, the image data before the smoothing process is stored in the input buffer 52 and sequentially transferred to the shift register 53. The data stored in the shift register 53 is sequentially transferred to the next stage pixel by pixel. Then, the combination of the coefficient register 50 and the multiplier array 54 corrects the optical characteristics of the pixels used in the smoothing process with reference to the correction target pixel (pixel D6 in the state of FIG. 24).

  For example, processing for correcting an optical characteristic having a relative light amount change of 1/100 with respect to the distance of one pixel is as follows. When the amount of light decreases from the pixel D6 toward the pixel D0 as shown in FIG. 25, when correcting the pixel D6, the light amount of the reference pixel D6 is set to 1, and the coefficient L-1 of the coefficient register 50 is 1.01. 1.02 is set to L-2, and 1.03 is set to the coefficient L-3.

  As a result, as shown in FIG. 26, the data of the pixels D3-D5 are output to the next-stage low-pass filter (LPF) processing block with the light amount corrected with reference to the data of the pixel D6. Become. The low-pass filter processing block is a product-sum operation circuit including a coefficient register 51, a multiplier array 55, and an adder 56. In the low-pass filter processing block, as described above, the coefficients in the coefficient register 51 are set so as to have LPF characteristics. In this example, the values of the coefficients are set to h0 = 1/2 and h-1 = 1 / 4, h-2 = 1/8, h-3 = 1/8. The smoothed data from the adder 56 is written to the output buffer 59 and written to the memory 8 via the data bus 3.

  A smoothing process will be described. The smoothing process is started from processing of data (D6) having a high compression rate adjacent to the boundary of the region. First, in FIG. 24, the data of the pixels D3-D6 is set in the shift register 53 in order to process the data of the pixel D6. After the data of the pixel D6 is corrected by the above procedure, the next pixel D7 is processed. In the processing of the pixel D7, the data of the pixel D7 is newly added to the shift register 53 and is simultaneously shifted by one data. Therefore, the processing is performed in a state where the data of the pixels D4 to D7 is set in the shift register 53.

  At this time, the change in the amount of light within the correction range is expressed by linear approximation as described above. Therefore, the set value of the coefficient register 50 for correcting the optical characteristics is used as it is. FIG. 27 shows the corrected data. In the present embodiment, as shown in FIG. 27, three data of pixels D6-D8 are within the processing range, and it is shown that smoothing has been achieved.

  Next, the second smoothing method according to the present embodiment will be described with reference to FIGS. In this smoothing process, the data change due to the optical characteristics is removed from the data before correction by the smoothing filter 5e (corresponding to the filter 5 in FIG. 1) shown in FIG. As in the case of the smoothing method 3, the step at the boundary is measured, the correction amount is obtained from the obtained step according to the pixel position of the data to be corrected, and the pre-correction data is obtained using the obtained correction amount. A smoothing process is performed by performing an addition (subtraction) process. However, when the obtained level difference is larger than a predetermined amount, it is determined that there is a level difference (such as an edge portion) in the image, and smoothing processing for the portion is not performed. This is different from the smoothing method.

  FIG. 28 shows the configuration of coefficient registers (coefficient registers 60 and 61 in FIG. 29) for correcting optical characteristics. 28A shows the configuration of the coefficient register 60 of FIG. 29, and FIG. 28B shows the configuration of the coefficient register 61 of FIG. In the light amount correction in the present embodiment, processing is performed using the pixel of the image closest to the boundary and having a low compression rate (in this description, the pixel D5 shown in FIG. 30) as the reference value (“1”). For this reason, the coefficient register 60 stores six correction values (M1 to M6) for pixels of an image with a high compression rate, and the coefficient register 61 stores correction values for pixels of an image with a low compression rate. Are stored for 5 data (M-1 to M-5).

  FIG. 29 shows the configuration of the filter 5e. The shift registers 63 and 64 store step detection data (D0 to D11) as shown in the figure. The image data with a high compression rate input to the shift register 63 is corrected by the coefficient register 60 and the multiplier array 65, added by an adder 67, and added to a subtractor 69. Similarly, image data with a low compression rate input to the shift register 64 is corrected by the coefficient register 61 and the multiplier array 66, added by the adder 68, and added to the subtractor 69. The subtracter 69 subtracts the output value of the adder 68 from the output value of the adder 67 to obtain a step output, and stores it in the step register 70.

  The value stored in the step register 70 is held for a period of smoothing of data (D6-D11) for one line. The step output from the step register 70 is applied to a determination circuit 71 and a multiplier 73. In the determination circuit 71, the input step output is compared with a predetermined reference determination value. When the step output is equal to or less than the reference determination value, smoothing processing is performed, and the step output exceeds the reference determination value. In this case, it is determined that there is a step in the original image, and the determination result is output to the subtraction coefficient setting circuit 72 so that smoothing processing is not performed.

  When the determination circuit 71 determines that smoothing processing is to be performed, the subtraction coefficient setting circuit 72 can select any of 3/24, 1/12, and 1/24 depending on the pixel position of the data to be processed (D6-D11). Is set as the subtraction coefficient. By this setting, the step data added to the subtracter 74 by the multiplier 73 is 3/4, 1/2, 1 of the average step (ΔY), as in the processing in the third smoothing method of the first embodiment. One of the values of / 4. The subtraction coefficient setting circuit 72 sets the output to 0 and sets the step data applied to the subtracter 74 to 0 when the determination circuit 71 determines that smoothing processing is not performed. In the subtracter 74, the output of the multiplier 73 is subtracted from the final stage output (D 6) of the shift register 63, and the subtraction result is stored in the output buffer 75.

  This will be described more specifically with reference to FIGS. FIG. 30 shows the state of data before correction. FIG. 30 shows the state of data when a subject is photographed with no average luminance change. The straight lines 105 and 106 in the figure are the average values of the data, and in this case, the inclination represents the optical characteristics. FIG. 31 shows the state of the data after the light amount adjustment. This is the output of the multiplier array 65 and the multiplier array 66 in FIG. 29, and the reference data (pixel D5 data (77)) is the same data value position (pixel D5 data (76) as in FIG. )It is in. Further, it can be seen that the straight lines 107 and 108 indicating the average value of the data are horizontal, and the change due to the optical characteristics is corrected.

  FIG. 32 shows the state of the data after correction. In the correction processing of this embodiment, ΔY × 3/4 is subtracted from the data of pixels D6 and D7, ΔY / 2 is subtracted from the data of pixels D8 and D9, and ΔY / 4 is subtracted from the data of pixels D10 and D11. In order to perform smoother smoothing processing, the subtraction processing can be performed by changing the subtraction coefficient in units of one pixel without changing the configuration of the filter 5e.

  As described above, according to the present embodiment, the smoothing process is performed after correcting the optical characteristics of the image data in consideration of the optical characteristics, so that the processing accuracy is improved and the accurate smoothing process is possible. Become. In addition, when the correspondence between the optical characteristics of the distortion optical system and the position of the divided area and the compression ratio is determined in advance and only the information for identifying the distortion optical system is included in the header data, it is recorded for smoothing processing. The header data to be processed is only information on the type of optical system, and the amount of header data can be reduced.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and includes design changes and the like without departing from the gist of the present invention. .

1 is a block diagram illustrating a configuration of an image reproduction device according to a first embodiment of the present invention. FIG. 5 is a reference diagram illustrating an image division range according to the first embodiment of the present invention. It is a reference figure which shows the correction range in the 1st Embodiment (1st smoothing processing method) of this invention. It is a reference diagram showing a pixel used in the first embodiment (first smoothing method) of the present invention. It is a block diagram which shows the structure of the coefficient register in the filter with which the image reproduction apparatus by the 1st Embodiment (1st smoothing method) of this invention is provided. It is a block diagram which shows the structure of the filter with which the image reproduction apparatus by the 1st Embodiment (1st smoothing method) of this invention is provided. It is a reference figure which shows the state of the data before correction | amendment in the 1st Embodiment (1st smoothing method) of this invention. It is a reference figure which shows the state of the data after correction | amendment in the 1st Embodiment (1st smoothing method) of this invention. It is a reference figure which shows the correction range in the 1st Embodiment (2nd smoothing processing method) of this invention. It is a reference figure which shows the procedure of the correction | amendment in the 1st Embodiment (2nd smoothing processing method) of this invention. It is a reference diagram showing a pixel used in the first embodiment (second smoothing method) of the present invention. It is a block diagram which shows the structure of the filter with which the image reproduction apparatus by the 1st Embodiment (2nd smoothing method) of this invention is provided. It is a reference figure which shows the state of the data before correction | amendment in the 1st Embodiment (2nd smoothing processing method) of this invention. It is a reference figure showing the state of the data after amendment in the 1st embodiment (the 2nd smoothing processing method) of the present invention. It is a block diagram which shows the structure of the filter with which the image reproduction apparatus by the 1st Embodiment (3rd smoothing method) of this invention is provided. FIG. 6 is a reference diagram illustrating a state of data before correction in the first embodiment (third smoothing method) of the present invention. It is a reference figure showing the state of the data after amendment in the 1st embodiment (the 3rd smoothing processing method) of the present invention. It is a block diagram which shows the structure of the distortion optical system in the 2nd Embodiment of this invention. FIG. 10 is a reference diagram illustrating a subject screen input to a distortion optical system according to a second embodiment of the present invention. It is a reference figure which shows the light reception screen output from the distortion optical system in the 2nd Embodiment of this invention, and projecting on the light-receiving surface of an image pick-up element. It is explanatory drawing for demonstrating light quantity distribution in the 2nd Embodiment of this invention. It is a reference figure which shows the light quantity distribution in the 2nd Embodiment of this invention, and the mode of area division. It is a block diagram which shows the structure of the coefficient register in the filter with which the image reproduction apparatus by the 2nd Embodiment (1st smoothing method) of this invention is provided. It is a block diagram which shows the structure of the filter with which the image reproduction apparatus by the 2nd Embodiment (1st smoothing method) of this invention is provided. It is a reference figure which shows the state of the data before correction | amendment in the 2nd Embodiment (1st smoothing processing method) of this invention. It is a reference figure which shows the state of the data in light quantity correction | amendment in the 2nd Embodiment (1st smoothing processing method) of this invention. It is a reference figure which shows the state of the data after correction | amendment in the 2nd Embodiment (1st smoothing method) of this invention. It is a block diagram which shows the structure of the coefficient register in the filter with which the image reproduction apparatus by the 2nd Embodiment (2nd smoothing method) of this invention is provided. It is a block diagram which shows the structure of the filter with which the image reproduction apparatus by the 2nd Embodiment (2nd smoothing method) of this invention is provided. It is a reference figure which shows the state of the data before correction | amendment in the 2nd Embodiment (2nd smoothing processing method) of this invention. It is a reference figure which shows the state of the data in light quantity correction | amendment in the 2nd Embodiment (2nd smoothing processing method) of this invention. It is a reference figure which shows the state of the data after correction | amendment in the 2nd Embodiment (2nd smoothing processing method) of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Memory card, 2 ... Card R / W circuit, 3 ... Data bus, 4 ... Decompression circuit, 5, 5a, 5b, 5c, 5d, 5e ... Filter, 6 ... Operation buttons, 7 ... arithmetic circuit, 8 ... memory, 9 ... TFT control circuit, 10 ... TFT, 11 ... compression circuit, 12 ... video output circuit

Claims (6)

Generated by dividing the image data output from the image sensor that received the optical image from the optical system into a plurality of areas and compression-coding each area with a predetermined compression ratio. The position and compression ratio of each area An image reproducing apparatus that decompresses compressed image data having header information indicating that
Filter means for smoothing a boundary between a first region and a second region adjacent to the first region among the plurality of regions in the decompressed image data based on the header information;
Based on the header information, setting means for setting a smoothing processing range for performing the smoothing in the filter means;
An image reproducing apparatus comprising:   The filter means performs the smoothing of the decompressed image data in the smoothing range across both the low compression ratio area and the high compression ratio area across the boundary. The image reproducing device according to claim 1.   2. The filter unit according to claim 1, wherein the filter unit smoothes only the decompressed image data within the smoothing range in the region with a high compression rate based on the decompressed image data in the region with a low compression rate. Image playback device.   The filter means obtains the difference between the average value of the decompressed image data in the region with a low compression rate and the average value of the decompressed image data in the region with a high compression rate as a step amount across the boundary, 2. The image reproducing apparatus according to claim 1, wherein the expanded image data within the smoothing processing range is processed according to the position of the expanded image data to be processed based on the step amount. The optical system is a strain optical system that optically compresses and collects a peripheral portion with respect to a central portion,
The header information includes optical characteristic information of the strain optical system,
The said filter means performs the smoothing after correcting the optical characteristics of the expanded image data within the smoothing processing range based on the header information including the optical characteristics information. The image reproducing device according to claim 4. Image data output from an image sensor that receives a light image from a strain optical system that optically compresses and collects the peripheral portion with respect to the central portion is preset according to the optical characteristics of the strain optical system. An image reproducing device that decompresses compressed image data generated by dividing into a plurality of regions and compressing and encoding each region at a predetermined compression rate and having header information indicating the optical characteristics, and reproduces the decompressed image data Because
Filter means for smoothing a boundary between a first region and a second region adjacent to the first region among the plurality of regions in the decompressed image data based on the header information;
Based on the header information, setting means for setting a smoothing processing range for performing the smoothing in the filter means;
An image reproducing apparatus comprising:

Images