| US 7,580,161 B2 | ||
| Method and apparatus for image processing | ||
| Hirokazu Shoda, Yokohama (Japan) | ||
| Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan); and Toshiba Tec Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Mar. 15, 2005, as Appl. No. 11/79,485. | ||
| Prior Publication US 2006/0209312 A1, Sep. 21, 2006 | ||
| Int. Cl. H04N 1/40 (2006.01) | ||
| U.S. Cl. 358—461 [382/309; 356/71] | 2 Claims |
| 1. An image processing method comprising steps of:
generating image signals using a photoelectric conversion element which has pixel columns of at least three lines;
detecting an amplitude of the image signal;
switching a gain of the photoelectric conversion element based on the amplitude; and
performing shading correction based on a formula A upon the gain being a first gain and based on a formula B upon the gain
being a second gain,
wherein the formula A is:
DLout=(DLin −black reference value)/(white reference value for low sensitivity−black reference value), where DLin is the amplitude
of the image signal and DLout is a result of the shading correction; and
wherein the formula B is:
DHout=(DHin−black reference value)/(white reference value for high sensitivity−black reference value), where DHin is the amplitude
of the image signal and DHout is a result of the shading correction.
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