Imaging device and method of processing imaging result in imaging device
The present invention relates to an imaging device and a method of processing an imaging result in an imaging device, and is applied to e.g. an electronic still camera to thereby allow the camera to correct image quality readily and flexibly with avoiding the deterioration of the image quality effectively. In the present invention, a three-dimensional look-up table is provided and an imaging result (Y 2 , Cb 2 , Cr 2 ) is corrected by use of the three-dimensional look-up table.
1. An imaging device, comprising:
an imaging element that outputs an imaging result of an optical image formed on an imaging plane; and
an image processor that implements color adjustment for the imaging result using a three-dimensional look-up table;
wherein the image processor includes:
an input-side color space converter that converts a color space of the imaging result from the imaging element, and outputs a resultant imaging result as data to be processed using the three-dimensional look-up table, and
an output-side color space converter that converts, using a reverse characteristic of a characteristic of the input-side color space converter, a color space of a processing result using the three-dimensional look-up table, and outputs a resultant imaging result.
2. The imaging device according to claim 1 , further comprising:
a memory that stores a plurality of kinds of correction data to be set in the three-dimensional look-up table; and
a controller that selects correction data from the plurality of kinds of correction data stored in the memory, and sets the selected correction data in the three-dimensional look-up table.
3. The imaging device according to claim 2 , further comprising a display unit that displays the imaging result, wherein the controller causes the display unit to display a menu including a plurality of kinds of items corresponding to the plurality of kinds of correction data, and accepts selection of an item by a user, and correction data that corresponds to the item selected by the user is set in the three-dimensional look-up table.
4. The imaging device according to claim 2 , wherein the controller selects the correction data to be set in the three-dimensional look-up table in accordance with an imaging condition that can be detected at the time of acquisition of the imaging result by the imaging element.
5. The imaging device according to claim 1 , further comprising:
a memory that stores a plurality of kinds of correction data to be set in the three-dimensional look-up table; and
a controller that creates correction data through interpolation arithmetic processing with use of the plurality of kinds of correction data stored in the memory, and sets the created correction data in the three-dimensional look-up table.
6. The imaging device according to claim 5 , further comprising a display unit that displays the imaging result, wherein the controller causes the display unit to display a menu including a plurality of kinds of items corresponding to the plurality of kinds of correction data, and accepts selection of a first item and a second item, the controller sets on the display unit a setting screen for an intermediate tone of the selected first and second items, and accepts setting of a weighting factor for the intermediate tone, and correction data produced through interpolation arithmetic processing with use of the weighting factor and correction data corresponding to the first and second items is set in the three-dimensional look-up table as the created correction data.
7. The imaging device according to claim 5 , wherein the controller sets an interpolation factor to be used for the interpolation arithmetic processing in accordance with an imaging condition that can be detected at the time of acquisition of the imaging result by the imaging element.
8. The imaging device according to claim 1 , further comprising a controller that sets correction data in the three-dimensional look-up table after weighting the correction data with a weighting factor, wherein the controller adjusts image quality of the imaging result by controlling the weighting factor.
9. The imaging device according to claim 8 , further comprising a display unit that displays the imaging result, wherein the controller causes the display unit to display a setting screen, and accepts setting of the weighting factor by input through the setting screen.
10. The imaging device according to claim 8 , wherein the controller sets the weighting factor in accordance with an imaging condition that can be detected only at the time of acquisition of the imaging result by the imaging element.
11. The imaging device according to claim 1 , further comprising a controller that adjusts image quality of the imaging result, wherein the image processor weights an output value from the three-dimensional look-up table with a weighting factor and outputs the weighted output value, and the controller controls the weighting factor to thereby adjust the image quality of the imaging result.
12. The imaging device according to claim 11 , further comprising a display unit that displays the imaging result, wherein the controller causes the display unit to display a setting screen, and accepts setting of the weighting factor by input through the setting screen.
13. The imaging device according to claim 11 , wherein the controller sets the weighting factor in accordance with an imaging condition that can be detected only at the time of acquisition of the imaging result by the imaging element.
14. The imaging device according to claim 1 , further comprising a controller that adjusts image quality of the imaging result, wherein the three-dimensional look-up table is a plurality of three-dimensional look-up tables, the image processor synthesizes output values from the plurality of three-dimensional look-up tables to thereby implement the color adjustment, and the controller controls a weighting factor for synthesis of the output values to thereby adjust the image quality of the imaging result.
15. The imaging device according to claim 14 , further comprising a display unit that displays the imaging result, wherein the controller causes the display unit to display a setting screen, and accepts setting of the weighting factor by input through the setting screen.
16. The imaging device according to claim 14 , wherein the controller sets the weighting factor in accordance with an imaging condition that can be detected only at the time of acquisition of the imaging result by the imaging element.
17. The imaging device according to claim 1 , wherein the image processor implements clipping, without changing a hue, for the imaging result that ranges beyond a range of a color space defined by a recording format of recording in the recording medium, and outputs a resultant imaging result, the clipping depending on setting of correction data set in the three-dimensional look-up table.
18. The imaging device according to claim 1 , wherein the three-dimensional look-up table is designed so that respective axes have different resolutions.
19. The imaging device according to claim 1 , wherein the image processor divides a color space of an imaging result from the imaging element into a plurality of areas, and determines which area the imaging result belongs to, and the image processor switches access to the three-dimensional look-up table depending on a determination result.
20. The imaging device according to claim 1 , further comprising a controller that sets correction data in the three-dimensional look-up table, wherein the controller creates the correction data by setting an imaging result obtained by another imaging device as a target value, and sets the created correction data in the three-dimensional look-up table.
21. The imaging device according to claim 1 , wherein the input-side and output-side color space converters are one-dimensional look-up tables.
22. The imaging device according to claim 1 , wherein the input-side color space converter processes the input image data using a non-linear input/output characteristic.
23. The imaging device according to claim 1 , wherein for color difference signals, a slope of the characteristic of the input-side color space converter is steeper near an achromatic axis and is less steep as the degree of chroma increases.
24. The imaging device according to claim 1 , wherein for a luminance signal, a slope of the characteristic of the input-side color space converter is steeper in high luminance regions.
25. A method of processing an imaging result in an imaging device, the method comprising:
outputting an imaging result of an optical image formed on an imaging plane;
implementing color adjustment for the imaging result using a three-dimensional look-up table, including:
converting a color space of the imaging result,
outputting a resultant imaging result as data to be processed using the three-dimensional look-up table,
converting, using a reverse characteristic of a characteristic used while converting the color space of the imaging result, a color space of a processing result using the three-dimensional look-up table, and
outputting a resultant imaging result.
26. An imaging device, comprising:
an imaging element that outputs an imaging result of an optical image formed on an imaging plane; and
an image processor that implements color adjustment for the imaging result using a three-dimensional look-up table;
wherein the image processor includes:
an input-side color space converter that converts a color space of the imaging result from the imaging element, and outputs a resultant imaging result as data to be processed using the three-dimensional look-up table so that a density of grid points in the three-dimensional look-up table is high in an area requiring highly-accurate image quality correction, and
an output-side color space converter that converts, using a reverse characteristic of a characteristic of the input-side color space converter, a color space of a processing result using the three-dimensional look-up table, and outputs a resultant imaging result.
27. The imaging device according to claim 26 , wherein the area requiring highly-accurate image correction is an area corresponding to an achromatic color.
28. The imaging device according to claim 26 , wherein the area requiring highly-accurate image correction is an area corresponding to a memory color.
29. The imaging device according to claim 26 , wherein for color difference signals of the imaging result, the characteristic of the input-side color space converter has a steeper slope near the achromatic axis and has a gentler slope as the degree of chroma increases.
30. The imaging device according to claim 26 , wherein for a luminance signal of the imaging result, the characteristic of the input-side color space converter has a steeper slope around important colors.
31. A method of processing an imaging result in an imaging device, the method comprising:
outputting an imaging result of an optical image formed on an imaging plane;
implementing color adjustment for the imaging result using a three-dimensional look-up table, including:
converting a color space of the imaging result, and outputting a resultant imaging result as data to be processed using the three-dimensional look-up table so that a density of grid points in the three-dimensional look-up table is high in an area requiring highly-accurate image quality correction,
converting, using a reverse characteristic of a characteristic used while converting the color space of the imaging result, a color space of a processing result using the three-dimensional look-up table, and
outputting a resultant imaging result.