Image processing method, encoding device, decoding device, and image processing apparatus

1. An image processing method, comprising:

in an image processing apparatus comprising one or more processors:

separating an image taken at a predetermined frame rate into a first frame and at least one second frame other than the first frame at intervals of 1/n, where n is an integer equal to or greater than 2;

calculating a low-frequency-component difference between the at least one second frame and the first frame;

performing signal processing designated by a user on the first frame;

decompressing, using a low-frequency component in the first frame being subjected to the signal processing and the low-frequency-component difference, a low-frequency component in the at least one second frame being subjected to the signal processing; and

decompressing, using the decompressed low-frequency component and a high-frequency component in the at least one second frame, the at least one second frame being subjected to the signal processing.

2. The image processing method according to claim 1 , further comprising performing the signal processing on a pixel in the at least one second frame, the pixel having the low-frequency-component difference equal to or above a threshold value from the first frame before the signal processing.

3. The image processing method according to claim 2 , further comprising decompressing the at least one second frame being approximately subjected to the signal processing comprising:

analyzing a frequency component in the at least one second frame to extract a pixel being a characteristics point;

performing the signal processing on the pixel; and

generating an interpolation value based on a signal processing result for replacement of a value of a pixel not being the characteristics point.

4. The image processing method according to claim 1 , further comprising scanning the image in a horizontal direction or in a vertical direction to determine a pixel as a characteristics point in each pixel group, wherein the pixel group is a region where a difference between a plurality of pixels adjacent to each other in the scanning direction is within a threshold range.

5. An encoding device, comprising:

a frame separation section configured to separate an image taken at a predetermined frame rate into a first frame and at least one second frame other than the first frame at intervals of 1/n, where n is an integer equal to or greater than 2;

a first frequency division section configured to divide each of the first frame and the at least one second frame into a low-frequency component and a high frequency component;

a difference generation section configured to generate difference data in low-frequency component between the at least one second frame and the first frame;

a compression and encoding section configured to compress and encode the difference data and the high-frequency component in the at least one second frame;

a first signal processing section configured to perform signal processing designated by a user on the first frame; and

a transmission section configured to transmit the difference data and the high-frequency component in the at least one second frame both being compressed and encoded, and the first frame being subjected to the signal processing.

6. The encoding device according to claim 5 , further comprising a second signal processing section configured to perform the signal processing on a pixel in the at least one second frame, the pixel having a low-frequency-component difference equal to or above a threshold value from the first frame.

7. The encoding device according to claim 6 , further comprising an in-frame compression signal processing section configured to decompress the at least one second frame being approximately subjected to the signal processing by: analyzing a frequency component in the at least one second frame to extract a pixel being a characteristics point, performing the signal processing on the pixel, and generating an interpolation value based on a signal processing result for replacement of a value of a pixel not being the characteristics point.

8. A system comprising:

an encoding device comprising:

a frame separation section configured to separate an image taken at a predetermined frame rate into a first frame and at least one second frame other than the first frame at intervals of 1/n, where n is an integer equal to or greater than 2;

a first frequency division section configured to divide each of the first frame and the at least one second frame into a low-frequency component and a high frequency component;

a difference generation section configured to generate difference data in low-frequency component between the at least one second frame and the first frame;

a compression and encoding section configured to compress and encode the difference data and the high-frequency component in the at least one second frame;

a first signal processing section configured to perform signal processing designated by a user on the first frame; and

a transmission section configured to transmit the difference data and the high-frequency component in the at least one second frame both being compressed and encoded, and the first frame being subjected to the signal processings; and

a decoding device comprising:

a separation section configured to separate information transmitted by the encoding device into compression codes of the difference data, compression codes of the high-frequency component in the at least one second frame, and the first frame being subjected to the signal processing;

an expansion section configured to expand the compression codes of the difference data and the high-frequency component in the at least one second frame;

a low-frequency component decompression section configured to decompress, using the difference data and the low-frequency component in the first frame being subjected to the signal processing, the low-frequency component in the at least one second frame being subjected to the signal processing; and

a frame decompression section configured to decompress, by an inverse operation of a frequency division, the at least one second frame being subjected to the signal processing, using the decompressed low-frequency component in the at least one second frame and the high-frequency component in the at least one second frame.

9. The system according to claim 8 , wherein the encoding device comprises a second signal processing section configured to perform the signal processing on a pixel in the at least one second frame, the pixel having a low-frequency-component difference equal to or above a threshold value from the first frame.

10. The system according to claim 9 , wherein the encoding device comprises an in-frame compression signal processing section configured to decompress the at least one second frame being approximately subjected to the signal processing by: analyzing a frequency component in the at least one second frame to extract a pixel being a characteristics point, performing the signal processing on the pixel, and generating an interpolation value based on a signal processing result for replacement of a value of a pixel not being the characteristics point.

11. An image processing method, comprising:

in an image processing apparatus comprising one or more processors:

separating an image taken at a predetermined frame rate into a first frame and a second frame other than the first frame at intervals of 1/n, where n is an integer equal to or greater than 2;

performing signal processing designated by a user on the first frame;

performing the signal processing on a pixel in the second frame, the pixel detected to have a difference of a threshold value or above based on a pixel-to-pixel comparison between the second frame and the first frame before the signal processing; and

decompressing the second frame being subjected to the signal processing by providing a pixel, not detected to have the difference of the threshold value or above, with a value of a pixel at the same position in the first frame being subjected to the signal processing.

12. An image processing apparatus, comprising:

a frame separation section configured to separate an image taken at a predetermined frame rate into a first frame and a second frame other than the first frame at intervals of 1/n, where n is an integer equal to or greater than 2;

a first signal processing section configured to perform signal processing designated by a user on the first frame;

a comparison section configured to make a pixel-to-pixel comparison between the second frame and the first frame before the signal processing;

a second signal processing section configured to perform the signal processing on a pixel in the second frame, the pixel detected to have a difference of a threshold value or above;

a copy processing section configured to provide a pixel not detected to have the difference of a threshold value or above, with a value of a pixel at the same position in the first frame being subjected to the signal processing; and

a combining section configured to combine an output from the second signal processing section and an output from the copy processing section to decompress the at least one second frame being subjected to the signal processing.