Color display system and image transforming device
AssigneeNational University Corporation Shizuoka University
InventorsYoshifumi Shimodaira, Takamori Shimazu
Life of this patent
Estimating the term…
Abstract
A color display system has an image transforming device transforming an image signal (XC, YC, ZC) of a XYZ colorimetric system to an image signal of a RGB colorimetric system and outputting the image signal of the RGB colorimetric system; and a display receiving the image signal of the RGB colorimetric system which has been output from the image transforming device. The image transforming device has: a converting part; a calculation part; a determination part; and a feedback part.
Claims3
A color display system comprising:
- an image transforming device transforming XC, YC, ZC of a XYZ image signal of a XYZ calorimetric system to an RGB image signal of a RGB calorimetric system and outputting the RGB image signal of the RGB calorimetric system;
- and
- a display receiving the image signal of the RGB calorimetric system which has been output from the image transforming device;
- wherein the image transforming device comprises:
- a converting part operable to convert XC, YC, ZC of the XYZ image signal by taking a gradation value between 0 and (2n−1) into RGB linear values using XYZ values corresponding to (2n−1), wherein the XYZ values corresponding to (2n−1) represent a maximum gradation value of each of RGB of the display, and further wherein the value, n, represents a number of bits of data being used to convert the XC, YC, ZC of the XYZ image signal;
- a calculation part operable to calculate Rd, Gd and Bd of the RGB image signal at gradation values d corresponding to the RGB linear values, wherein the calculating is performed by:
- using measurement data between gradation values and corresponding XYZ values of each of RGB of the display;
- obtaining (Xrd, Yrd, Zrd), (Xgd, Ygd, Zgd) and (Xbd, Ybd, Zbd) XYZ values at the gradation values d using the measurement data;
- and
- deriving values for a, b and c from
- XC=aXrd+bXgd+cXbd,
- YC=aYrd+bYgd+cYbd, and
- ZC=aZrd+bZgd+cZbd;
- a determination part operable to determine whether the a, b and c found in the calculation part are all within a predefined tolerance range, wherein the predefined tolerance range includes 1, and, in case the a, b, and c found in the calculation part are within the range, outputting the Rd, Gd and Bd as true values of the RGB image signal of the RGB colorimetric system corresponding to the XYZ image signal of the XYZ calorimetric system;
- and
- a feedback part for feeding back the calculation results a, b and c to the calculation part to perform the calculation again when determined to be out of the range by the determination part.
An image transforming device transforming an XC, YC, ZC of a XYZ image signal of a XYZ calorimetric system to an RGB image signal of a RGB colorimetric system and outputting the RGB image signal of the RGB calorimetric system to a display comprising:
- a converting part operable to convert the XC, YC, ZC of the XYZ image signal by taking a gradation value between 0 and (2n−1) into RGB linear values using XYZ values corresponding to (2n), wherein the XYZ values corresponding to (2n−1) represent a maximum gradation value of each of RGB of the display, and further wherein the value, n, represents a number of bits of data being used to convert the XC, YC, ZC of the XYZ image signal;
- a calculation part operable to calculate Rd, Gd and Bd of the RGB image signal at gradation values d corresponding to the RGB linear values using measurement data between gradation values and XYZ values of each of RGB of the display, obtaining (Xrd, Yrd, Zrd), (Xgd, Ygd, Zgd) and (Xbd, Ybd, Zbd) XYZ values at the gradation values d using the measurement data, and deriving a, b and c from
- XC=aXrd+bXgd+cXbd,
- YC=aYrd+bYgd+cYbd, and
- ZC=aZrd+bZgd+cZbd;
- a determination part operable to determine whether the a, b and c found in the calculation part are all within a predefined tolerance range, wherein the predefined tolerance range includes 1, and, in case the a, b, and c found in the calculation part are within the range, outputting the Rd, Gd and Bd as true values of the image signal of the RGB calorimetric system corresponding to the image signal of the XYZ colorimetric system;
- and
- a feedback part for feeding back the calculation results a, b and c to the calculation part to perform the calculation again when determined to be out of the range by the determination part.
Dependencies are inferred from the claim text.