Black value extension device for image processing by determining gradients based on minimum value and change-over point for frame

摘要

An image signal is received and a frame minimum value and maximum value or a dark area average value are extracted. A change-over point is extracted which delimits the dark region to be expanded. Then a first gradient is determined based on the frame minimum value and the change-over point, and a user-side gradient influence parameter is determined. Using these gradients, the black value of the image signal is stretched. Independent claims are included for a black value expansion device and method.