Patent ID: 7911540
Filing Date: 2011-03-22
Classification: G06T,H04N

Abstract:
1. A tone conversion apparatus that converts an image signal having a first number of bits into an image signal having a second number of bits, the second number of bits being larger than the first number of bits, the apparatus comprising: a decision-processing section that sequentially detects a signal level difference between pixels of an image in a predetermined direction thereof by using the image signal having the first number of bits, determines whether the signal level difference remains within a preset signal level difference, and determines a pixel which has the same signal level as that of an immediately preceding pixel that encounters the signal level difference and is consecutive with the immediately preceding pixel if the signal level difference remains within the preset signal level difference; and a bit-allocation-processing section that adds a bit to the least significant bit of the image signal having the first number of bits to convert the image signal having the first number of bits into the image signal having the second number of bits, divides the signal level difference when the signal level difference remains within the preset signal level difference, and uses a result of the division to set the signal level difference between the consecutive pixels to the consecutive pixels determined by the decision-processing section.