PURPOSE: To ensure image display data of a necessary number of bits and to display an infrared image of high quality by calculating bit shift quantity from the max. value of operation result data and shifting the same toward the most significant bit.
CONSTITUTION: An infrared sensor 21A detecting infrared rays converts an infrared image signal SA to digital data by an A/D converter 21B to input the digital data to a data correction system 22 for example, as image data DA of n=10 bits. Next, sensitivity correction data DB of 12 bits is read from a memory 22B and the data DA, DB are multiplied by a DSP 22C to obtain operation result data DC of 22 bits. Subsequently, the max. value of the data DC and the bit position thereof are calculated to obtain bit shift quantity, for example, Y=2. The data DC is shifted toward the most significant bit by 2 bits and the image display data DouT of m=8 bits required by a display device 23B is outputted to display an infrared image of 8-bit resolving power.
DOI SHOJI
AWAMOTO KENJI
YONEYAMA KISHIO
