In a pre-procedure in an image communication method, a receiver notifies a transmitter as to whether a capability of receiving JPEG-encoded information is provided, whether a capability of receiving full-color information in Lab color space is provided, whether a capability of receiving full-color information in sYCC color space is provided, and whether a capability of receiving non-regular-sized information in sYCC color space is provided. Furthermore, the transmitter notifies the receiver as to designation of transmission of JPEG-encoded data, designation of transmission of full-color information in Lab color space, designation of transmission of full-color information in sYCC color space, and designation of transmission of non-regular-sized information in sYCC color space. An upper limit of information amount of non-regular-sized information in a main scanning direction is determined based on a maximum receivable sheet size and resolution of full-color information in Lab color space.