Abstract: A read-out operation is carried out in which a stimulable phosphor sheet having a radiation image stored thereon is exposed to stimulating rays, which cause it to emit light in proportion to the amount of energy stored thereon during its exposure to radiation, the emitted light is photoelectrically detected and read-out image signal is thereby obtained. A reproducing operation is then carried out in which the read-out image signal is used to reproduce a visible radiation image. A radiation image read-out and reproducing method comprises the steps of carrying out processing which obtains information from the read-out image signal, said information being used to determine the conditions under which image processing is to be conducted, and at least one type of image processing, which can be conducted without the information being used, during the period of time from when the read-out operation is being carried out to when the reproducing operation is begun.

Abstract: In a system for compressing radiation image signals, code tables for use in entropy encoding for signal compression are created and classified in accordance with combinations of human body portions of radiation images with image recording conditions thereof. The optimal table is selected from the classified tables in accordance with the combination of the human body portion of the radiation image with the image recording conditions thereof which are inputted from a keyboard. Radiation image signals obtained by reading out the radiation image are compressed by use of the optimal table, thereby quickly achieving efficient signal compression.

Abstract: Unsharp masking operations of original video signals are performed by a couple of processor systems (100, 200), which are interconnected in cascades logically to share the burden of the operations. One processor system (100) in the preceding stage executes a part of unsharp masking operations by accumulating the original video signals with respect to the pixels involved in an original image to transfer the resultant data together with the associated original video signals to the other processor system (200) in the subsequent stage. The other processor system (200) receives those data and proceeds the remaining operations required for the unsharp masking operations including averaging by simple or weighted addition. Those operations are executed with respect to all unsharp masks involved in the original image.