Since Krita 1.5 we are capable to open HDR (High-Dynamic-Range) image and do basic visualization and some manipulation. But, we want to make Krita 2 a fully capable HDR image editor, from creation, manipulation and conversion. For creation, since a while we are capable to create HDR from a bracketing of LDR (Low-Dynamic-Range) photo, for conversion, I have started to add some tonemapping algorithms coming either from last year OpenICC google summer of code or from pfstmo, but that’s a story for an other time.
Today I will speak about painting on an HDR image. While it was theoretically possible to do it in 1.6, it was not possible to select a color outside the normal range. Individual selection of the channel value isn’t intuitive with a classical image, artist use visual mean to select the color. It’s even worse with HDR image, because the value of each channel contains color information as well as amount of light. But the amount of light can be separated from the color information, that’s how we do it in Krita. In fact, as you can see on the video bellow, the user select the “exposure” on the overview docker, then the color in the color selector, and when the user draw the color selected is adjust to the current exposure, that way the color painted correspond precisely to the color selected.
On a side note, that change also allow to select the exposure you want to use when converting back to a classical LDR image for export. And for hardcore users, a color selector based on channel values is probably going to be added latter.