An image data processing method and apparatus for performing image correction processes for a restored image data file obtained from a JPEG-compressed image data file which may prevent block distortions and provide a high quality image. When during the second action the internal cold storage temperature reaches a minimum temperature Tmin, the refrigeration system stops a compressor and performs a third action. A processing system converts the inflow and outflow rates into incremental volume changes in the volume of the heart ventricle and adds and subtracts the incremental volume changes from a relative volume of the heart ventricle to study volume changes in the explanted heart while it is beating. Each snooper is capable of responding at different times. The ring as well as the necklace and the bangle are each formed with one or more bores into which one of the stud earrings can be inserted and is retained releasably therein. The color filter has an opening with the protrusion inserted therein such that the color filter is fixed between the first and second carriers.