A CCD captures a subject image passed through a taking lens and an image processing circuit performs various types of image pre-treatment including gamma correction and white balance on image data corresponding to n lines×m rows output by the CCD. The image processing circuit performs format processing on the data which are then compressed at a compression circuit. The white balance adjustment is implemented in line sequence at a line processing circuit which engages in signal processing in pixel sequence in units of individual lines in the output from the CCD. The image data having undergone the pre-treatment are subjected to format processing prior to JPEG compression, at a block processing circuit that engages in signal processing in units of individual blocks each ranging over an n×m (N>n, M>m) block. The signal processing is performed in block sequence.