Image processing apparatus and gradation reproduction method
AssigneeSeiko Epson Corporation
InventorJun Hoshii
Life of this patent
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Abstract
The purpose of this invention is to reproduce gradations of dark parts between devices with different ranges of reproducible brightness. The range of reproducible brightness by the printer is a range from Lblack to 100, and this is narrow in relation to the range of brightness that is able to be reproduced by the digital camera (0 to 100). An image processing apparatus converts the input brightness Linput on the input brightness graph Linput-graph to the output brightness Loutput on the output brightness graph Loutput-graph. Accordingly, the low brightness gradations 0 to Lblack of the input brightness Linput in relation to the input RGB values included in the range R1 become Lblack to L1, the dark area gradations are reproduced.
Claims7
An image processing apparatus that outputs input image data to an output device, wherein the input image data is input from an input device, wherein the input device has a input brightness area that is reproducible by the input device, wherein the output device has a output brightness area narrower than the input brightness area and is reproducible by the output device, the image processing apparatus comprising:
- a first color conversion processing module that converts the input image data to first intermediate image data, wherein the input image data is expressed using a input device dependent color space that depends on the input device, wherein the first intermediate image data at least expresses the brightness of the input image data and is expressed by an device independent color space that does not depend on each device,
- a brightness conversion module that converts the first intermediate image data to second intermediate image data so that gradation of first brightness is expressed in the output brightness area, wherein the first brightness is, of the first intermediate data, at least lower than the minimum value of the output brightness area, and
- a second color conversion processing module that converts the second intermediate data to output image data to output to the output device, wherein the output image data is expressed using an output device dependent color space that depends on the output device.
A gradation reproduction method by an image processing apparatus, wherein the image processing apparatus that outputs input image data that is input from an input device to an output device, wherein the input device has a input brightness area that is reproducible by the input device, wherein the output device has a output brightness area narrower than the input brightness area and is reproducible by the output device the gradation reproduction method comprising the steps of,
- converting the input image data to first intermediate image data, wherein the input image data is expressed using a input device dependent color space that depends on the input device, wherein the first intermediate image data at least expresses the brightness of the input image data and is expressed by an device independent color space that does not depend on each device,
- converting the first intermediate image data to second intermediate image data so that gradation of first brightness is expressed in the output brightness area, wherein the first brightness is, of the first intermediate data at least lower than the minimum value of the output brightness area, and
- converting the second intermediate data to output image data to output to the output device, wherein the output image data is expressed using an output device dependent color space that depends on the output device.
Dependencies are inferred from the claim text.