It would help if I could see the actual image. Usually when I see a histogram like this, there either is a lot of pure white or pure black, and a very skinny line on the histogram at the edges, representing the white or black pixels. Is that a line at the far right, representing the white pixels? You did say the image was washed out, maybe with too much white?
If you don't already know, you can go [colors->info->colorcube analysis] and see how many colors are in the image, if that helps.
There are two images here. Before I adjust the contrast and after. After I raised the contrast the white pixels get blown out and the histogram changes like yours
If you don't already know, you can go [colors->info->colorcube analysis] and see how many colors are in the image, if that helps.
There are two images here. Before I adjust the contrast and after. After I raised the contrast the white pixels get blown out and the histogram changes like yours