The GIMP Dimage color plugin converts JPEG/TIFF files
produced by the Minolta DiMAGE 5/7 digital camera into sRGB
colorspace. The process consists in:
- Applying the inverted DiMAGE gamma curve to input RGB
- Converting the linearized RGB values into sRGB (Gamut
- Applying the contrast correction ("iTRC") curve *;
- Applying the sRGB gamma curve.
The highlighted area in Fig. 1 corresponds to the colors
that the DiMAGE can capture. The area inside the black
triangle corresponds to the colors displayable in sRGB colorspace.
* The contrast correction curve can be found in ICC
profiles provided by Minolta with the Dimage Viewer Utility. It
correspond to a tag ("iTRC") which is not part of the ICC
specifications. This explains why softwares like the lcms library
or Photoshop can't properly handle those profiles.
Fig. 1: DiMAGE and sRGB color gamuts
Fig. 2: Gamma and iTRC curves