1. A recording apparatus comprising: recording means for recording an image on a recording medium on the basis of recording data; input means for inputting image data from an image data source; image processing means for decoding the image data inputted by said input means and executing image processing on the decoded image data to generate recording data; and control means for outputting the recording data to said recording means to record an image, wherein said image processing means comprises a digital signal processor and a memory, and the digital signal processor executes an arithmetic operation for color space conversion processing and binarization processing of one pixel unit and stores the result of the arithmetic operation into the memory, by one instruction, wherein in the binarization processing, the digital signal processor compares a gray scale value of the image data with a threshold value and subtracts the gray scale value from a predetermined value and stores the result of the subtraction into the memory in accordance with the comparison result, by one instruction, with respect to each color component of the image data.