In this paper, we present a low-complexity open-loop Intermediate Dynamic Range (IDR) infrared image coding algorithm which provides two scalability layers. The first layer corresponds to a low dynamic range (LDR) version of the image which can be obtained by a JPEG decoder, while the second layer corresponds to the original IDR image. To achieve bit-depth scalability, we separate an input IDR image into LDR and residual images by simple operations, so that the residual image has a bit depth not higher than 8 bits per pixel, i.e., it can be compressed by JPEG baseline or other coding algorithm, developed for 8-bit depth formats. For real-time applications, we introduce a predefined look-up table containing quality factors for both the LDR and the residual images, so that increase of the table index corresponds to reduction of bit rate and increase of distortion close to an operational rate-distortion curve. Experimental results show that the proposed algorithm is significantly less complex than JPEG-XT Profile C, part 6, and provides better coding performance than its reference software with default tone mapping operator for the vast majority of the infrared test images.
- Infrared image coding