On Thu, 22 Feb 2001, Seth Burgess <sjburges@xxxxxxxxx> wrote: > I know you're trying to make a point, but I'd actually > agree with that assessment too, if for slightly > different reasons. The user has no way of knowing > what shade of gray they are about to place on the > image. I don't think this is used anywhere near as > commonly as layers/transparency, so isn't perceived as > such a big problem. But it should get some attention > as well. [...] It is even worse when you are working with indexed images (yes, there are people who are working with GIF images) because you can use only a limited set of colors and many tools do not work as expected. In fact, the support for indexed images in the Gimp is not very good, but in some cases it is better to live with the limitations of the indexed mode than converting to RGB and then back to indexed. For example, some games require a fixed palette, or sometimes you need to assign a specific index value to some pixels. I don't think that converting everything to RGB automatically is a good solution. It is not the solution for indexed images and not for grayscale images either. Now, about the alpha channel... When I posted my first message in this thread, I vaguely remembered what we discussed last year and I though that always adding an alpha channel would be the best solution. However, I re-read the discussion from last year and I saw that at that time I proposed to add an alpha channel as soon as a second layer is added, but not before. You can read the old thread with the subject ``Is "Add alpha channel" really necessary?'' on this page: http://lists.xcf.berkeley.edu/lists/gimp-developer/2000-May/date.html I think that it makes more sense to add an alpha channel when a second layer is created, not before (but I could change my mind again :-). Basically, we have to choose the lesser of two evils: 1) Adding an alpha channel to all images (even with a single layer) will confuse some users who think of their images as "flat" things (no layers, no transparency). They would see that the new version of the Gimp adds transparent areas when they use the eraser or when they cut a selection. And then they would be told to flatten their image before saving it, because the file format they are using did not support transparency. 2) Adding an alpha channel as soon as a second layer is added will confuse some users when they see that adding a layer causes the eraser or the cut operation to behave differently on the background layer (actually, they would behave in the same way as in all other layers, but not as they did before when the image was flat). I don't think that the second case is a real problem. These users already know about about layers and transparency, and they will expect all layers to behave in the same way. I think that the current situation is worse, because the background layer behaves differently from all other layers until you explicitely use "Add Alpha Channel". If you read the discussion from last year, you will see that I was surprised to discover that some users used the following solution when they did not understand why the background layer was behaving differently: they duplicated the background layer, then deleted the original one. For them, it was faster (two mouse clicks) and (surprisingly) more intuitive than finding "Add Alpha Channel" in some menu. I think that confusing the first category of users (those who do not think in terms of layers) would be worse. Many users are still using the Gimp as they would use xv, Windows Paint or other simple tools: they do not care about layers and they do not even know what they mean. I have witnessed this when I observed several of my colleagues using the Gimp. Although the concept of layers is powerful and simple to understand, this is simply not necessary for many users (not professionals, just casual users -- and this is the majority). -Raphael
