摘要 |
An apparatus for converting gray levels of an image, a method thereof, a program storage device thereof, and an infrared camera. The object of the present invention is to provide an apparatus for converting gray levels into fewer gray levels without missing a local gradation, a method thereof, a program storage device thereof, and an infrared camera to which the present invention is applied. A positive mask image (C) and a reversed mask image (C') are obtained the edge detected image (B) which is produced by emphasizing edges of an original image (A). A low frequency component (D) is obtained by performing an edge preserving smoothing operation for A masked with C, and performing a non-edge preserving smoothing operation for A masked with C'. A high frequency component (E) is obtained by calculating of (A - D). After D is compressed to D' and E is emphasized to E', an output image (F') is obtained by adding D' and E'. <IMAGE> |