I have to work with grayscale
.pfm (Portable Bitmap) images that apparently Gimp can open.
However, values are way higher than 1, like in range
[1;280]. So every pixel appears white, with % values for red, green and blue like 150%.
How can I rescale Gimp colors for rendering only, like a pixel with value
280.0 will be white and a pixel
1.0 black ?