Prologue
High dynamic tone mapping is a kind of graphical thesis to indemnify exposure of whole a image specially such as 256 leveled Red, Green, Blue (+Alpha transparency) formats. But high dynamic calculates all pixel levels as an floating point number with luminance ( in case of RGB, it convert each color channels to a luminance level ) to enhance for more dynamic ranged.
Programming
Examined all algorithms and refered to Free Image 3 library for how to make it as C++ code. Proceeded to stand-alone codes and finally embedded to my open source project, librawprocessor at my github repository.
Testing results
As my experimental study, High dynamic tone mapping was enhances low exposed/qulity medical images to fully ranged pixel levels in same min/max range.
Left image is original digital medical chest PA TFT detector image and it could be ranged about 0 to 2700.
Right image is processed Reinhard alogortihm (with parameters : contrast 1.0 and adaptation 0.5) to expand dynamic range.
Pixel levels spreads down to about 6500 without high peak as above image. Every pixel levels be flatten. It will be expected to better for adjust post image processing with less loses.
Also it much better to examine anatomy with no special signal processing. Just doing thresholding window leveling makes good result to check organs.
Used program:
- My medical raw image viewer, open source in bitbucket, also free download availed.
- librawprocessor, supports AVX SIMD, OpenMP, 64bit all.