SIGNAL PROCESSING DEVICE

PROBLEM TO BE SOLVED: To provide a signal processing device capable of highly accurately calculating, when an image is spread due to acquisition conditions such as imaging characteristics of an optical system or image deletion, a target signal component having the spread, and outputting the target signal component as an absolute value.SOLUTION: A signal integration unit 1 calculates, for an input pixel included in an input image 5, the sum of pixel values within a surrounding calculation range around the pixel. A low-pass filter 2 calculates, from the input image 5, an offset component of a pixel value within an offset component calculation range equal to the calculation range of the signal integration unit 1. A background integration unit 3 calculates a product of the calculated value of the low-pass filter 2 and a preset background coefficient value 6. A difference signal output unit 4 calculates a difference between the calculated value of the signal integration unit 1 and the calculated value of the background integration unit 3, and outputs the calculated value of the difference as an output signal 7.