The image data transmission method provided by embodiments of the present disclosure is used in the image processing device, and includes steps of: acquiring a fixation region and a non-fixation region on a display screen of the display device; compressing image data of a to-be-displayed image corresponding to the non-fixation region to acquire image data at a second resolution; and combining the image data at the second resolution with image data of the to-be-displayed image at a first resolution corresponding to the fixation region, and outputting the combined image data to the display device, the first resolution being substantially greater than the second resolution.