Image processing device, method, and program deciding a processing parameter
[Object] To prevent an inappropriate processing parameter from being used in a case in which an image that may be expressed by various expression methods is handled. [Solution] Provided is an image processing device including: a control unit that decides a processing parameter for image processing performed on an image on the basis of at least one of a transfer function related to conversion between light and an image signal that is applied to the image or a color range that is applied to the image; and a processing unit that executes the image processing using the processing parameter that is decided by the control unit.
1. An image processing device comprising:
circuitry configured to:
decide a processing parameter for image processing performed on an image based on at least one of (i) a transfer function related to conversion between light and an image signal that is applied to the image or (ii) a color range that is applied to the image; and
execute the image processing using the decided processing parameter, the decided processing parameter representing a gain of a quantization step, the quantization step being adjusted strictly to a smaller value as the gain increases.
2. The image processing device according to claim 1 , wherein the circuitry is further configured to decide the processing parameter based on a combination of the transfer function and the color range.
3. The image processing device according to claim 1 , wherein the circuitry is further configured to decide the processing parameter such that influences of a change in a code value of the image signal due to a difference in the at least one of the transfer function or the color range on the image processing are canceled.
4. The image processing device according to claim 1 , wherein the circuitry is further configured to execute quantization processing on a partial region in the quantization step that is adjusted in accordance with a coding difficulty of each partial region of the image.
5. The image processing device according to claim 4 , wherein the circuitry is further configured to decide the gain of the quantization step for the image based on the at least one of the transfer function or the color range.
6. The image processing device according to claim 5 , wherein the circuitry is further configured to execute the quantization processing on each partial region in the quantization step after adjustment in which the quantization step is adjusted based on the gain and the coding difficulty of each partial region.
7. The image processing device according to claim 1 , wherein the circuitry is further configured to execute pixel classification processing on the image using the processing parameter.
8. The image processing device according to claim 7 , wherein the processing parameter includes a threshold value to be compared with a code value of a color component in the pixel classification processing.
9. The image processing device according to claim 8 ,
wherein the pixel classification processing includes region detection processing for detecting a specific region in the image, and
the threshold value includes a region detection threshold value.
10. The image processing device according to claim 9 ,
wherein the specific region is a region of a specific color, and
the region detection threshold value includes a color determination threshold value.
11. The image processing device according to claim 10 ,
wherein the specific color is a skin color, and
the color determination threshold value includes a skin color determination threshold value.
12. The image processing device according to claim 11 , wherein the circuitry is further configured to execute quantization processing on the image in the quantization step that is adjusted based on a result of the region detection processing.
13. The image processing device according to claim 1 , wherein the circuitry is further configured to store a value of the processing parameter associated with one or both of the transfer function and the color range.
14. The image processing device according to claim 1 , wherein the circuitry is further configured to determine a type of the at least one of the transfer function and the color range based on input information related to the at least one of the transfer function or the color range and decides the processing parameter for the image processing based on the determined type.
15. The image processing device according to claim 14 , wherein the input information is information acquired via a user interface.
16. The image processing device according to claim 14 , wherein the input information is information acquired from an auxiliary signal that is multiplexed with an input image signal that expresses the image.
17. An image processing method comprising:
deciding a processing parameter for image processing performed on an image based on at least one of (i) a transfer function related to conversion between light and an image signal that is applied to the image or (ii) a color range that is applied to the image; and
executing the image processing using the decided processing parameter, the decided processing parameter representing a gain of a quantization step, the quantization step being adjusted strictly to a smaller value as the gain increases.
18. A non-transitory computer readable medium storing computer readable instructions thereon that, when executed by a processor of an image processing device, causes the processor to perform a method comprising:
deciding a processing parameter for image processing performed on an image based on at least one of (i) a transfer function related to conversion between light and an image signal that is applied to the image or (ii) a color range that is applied to the image; and
executing the image processing using the decided processing parameter, the decided processing parameter representing a gain of a quantization step, the quantization step being adjusted strictly to a smaller value as the gain increases.