1. An electronic camera apparatus comprising: an image capturing unit to capture a first image of an object and outputs image data; an ROI recognition unit to recognize a region of interest (ROI) of the image data using a plurality of different ROI recognition methods; an ROI control unit to select one ROI recognition method from the different ROI recognition methods according to a function related to image capture of the object or a user designation and set ROI information based on a recognition result obtained by the selected ROI recognition method; and a compression unit to perform a compression process on the image data according to the ROI information set by the ROI control unit; wherein the ROI recognition unit uses the selected ROI recognition method to recognize the ROI based on a movement determination threshold, a significant contrast determination threshold, and a range enlargement extent specified by a user of the electronic camera apparatus by detecting a region of the image data in which there is movement based on a comparison between the image data and image data from a second image immediately preceding capture of the first image, detecting a range of the image data of the first image that has a significant contrast and includes the detected region in which there is movement, enlarging the detected range, and using the enlarged range as a base region.