05-30-2018, 09:23 PM
OfnutsThe problem with the linear histogram if that the most frequent value is 1. If you have a white background, 50% of your pixels are white. The other 255 values are usually at best at 2%, so hardly visible (1/50th of the total height). For the difference with RT, one explanation could be that Gimp is showing you the gamma-corrected histogram (the other pair of icons, next to linear/log).
It is true that RT does not offer a choice between linear & logarithmic. It seems like it might be one or the other if not something else. This caused me to undertake some more experiments which lead to another finding that might be worthy of some explanation. As it turns out both GIMP and RT do allow for display of Red, Blue, and Green channels separately. When I do that the histograms for both the Red and Green look quite similar for both GIMP and RT. However, the Blue channel could not be much more different. Furthermore the GIMP Blue channel looks pretty much like the situation that provoked the post where I basically just didn't see anything.
Following are 3 images that show side by side comparisons the Red, Blue and Green histograms for both GIMP and RT made from the same image as referenced previously. It looks to me like something is amiss. What do you think?
It is true that RT does not offer a choice between linear & logarithmic. It seems like it might be one or the other if not something else. This caused me to undertake some more experiments which lead to another finding that might be worthy of some explanation. As it turns out both GIMP and RT do allow for display of Red, Blue, and Green channels separately. When I do that the histograms for both the Red and Green look quite similar for both GIMP and RT. However, the Blue channel could not be much more different. Furthermore the GIMP Blue channel looks pretty much like the situation that provoked the post where I basically just didn't see anything.
Following are 3 images that show side by side comparisons the Red, Blue and Green histograms for both GIMP and RT made from the same image as referenced previously. It looks to me like something is amiss. What do you think?