Patent ID: 7639871

Claim:
A method for eliminating color shift phenomenon that produces due to high or lower brightness in an image, comprising: transforming an image datum into a frequency domain with a brightness signal and a chrominance signal; setting a brightness upper limit value and a brightness lower limit value, a upper limit brightness adjusting rate for a brightness value that is greater than or equal to the brightness upper limit value, a lower limit brightness adjusting rate for a brightness value that is smaller than or equal to the brightness lower limit value, and a linear brightness adjusting rate for a brightness value that is between the brightness upper limit value and the brightness lower limit value; judging the relationship between a brightness value of each pixel and the brightness upper limit value and between the brightness value of each pixel and the brightness lower limit value; wherein if one part of a brightness value of the pixel is besides the brightness upper limit value, one part of the chrominance signal corresponding to the one part of the brightness value of the pixel is adjusted according to the upper limit brightness adjusting rate; wherein if another part of the brightness value of the pixel is besides the brightness lower limit value, another part of the chrominance signal corresponding to the another part of the brightness value of the pixel is adjusted according to the lower limit brightness adjusting rate; wherein if the other part of the brightness value of the pixel is between the brightness upper limit value and the brightness lower limit value, the other part of the chrominance signal corresponding to the other part of the brightness value of the pixel is adjusted according to the linear brightness adjusting rate; and transforming the image datum that has been adjusted into an image file with a predetermined format.