An image processing device includes a first control circuit to transfer image data of a plurality of color components on a line basis in a main scanning direction, and a second control circuit connected to the first control circuit to process the image data of each one of the plurality of color components transferred from the first control circuit and output the processed image data on a line basis on an object. The first control circuit includes a plurality of registers provided for each one of the plurality of color components, a calculation circuit connected to the plurality of registers, a plurality of addition circuits provided for each one of the plurality of color components and connected to a corresponding one of the plurality of registers and the calculation circuit, and a transfer control circuit connected to the calculation circuit and the plurality of addition circuits.

A signal processing method includes addition of noise obtained by multiplying generated random number by K to the input pixel signal I(x), a binarization process of comparing the result of the addition with two thresholds, and a process of calculating a probability. The binarization process includes a first nonlinear process and a second nonlinear process. The first nonlinear process outputs P in a case where I(x) after the addition of the noise is greater than the threshold T1 and less than the second threshold T2. The second nonlinear determines 1 or 0 for a processing target pixel, in which the result of the first nonlinear process is P, based on input pixel signals of pixels around the processing target pixel. The process of calculating a probability calculates a probability J(x) that the result of the first nonlinear process is 1, or the result of the first nonlinear process is P and the result of the second nonlinear process is 1.

An image processing device includes a first control circuit to transfer image data of a plurality of color components on a line basis in a main scanning direction, and a second control circuit connected to the first control circuit to process the image data of each one of the plurality of color components transferred from the first control circuit and output the processed image data on a line basis on an object. The first control circuit includes a plurality of registers provided for each one of the plurality of color components, a calculation circuit connected to the plurality of registers, a plurality of addition circuits provided for each one of the plurality of color components and connected to a corresponding one of the plurality of registers and the calculation circuit, and a transfer control circuit connected to the calculation circuit and the plurality of addition circuits.