Core Image filters
Posted: Sun Jun 02, 2013 11:19 pm
I was having trouble figuring out how to get two images to participate in Core Image composite filters. What I finally figured out (just now) is that you pick a filter, and then drop another image onto the the Background Image target (which is the destination image, yes?). So. This is either a help request or an enhancement request. First, if I then select a different filter, the background image gets reset to the current source image, so every time I pick a filter, I have to drop the destination onto the background target, which is tedious. Second, it'd be really nice if, when I drop the destination image onto the background image target, I saw previews of all the composite filters in the filter selection pane. Third, if we had those previews, it'd be nice if the full CI filter set were in the selection pane. I'm using CI filters dynamically in an app, and the GC feature is really handy for working out the filters that I need to use, instead of trial and error and recompilation. So while (for example) Source In and Destination In are in a sense redundant (S*Da vs D*Sa), the ability to preview them simultaneously would be convenient. Since there are only 28 CI composite filters vs the 23 in the GC table, it's not that many more. And some quibbles (or confusions on my part): some filter names don't fit in the panel columns, and it takes hovering to see what they are. Maybe just leave off the suffix "Blend Mode"? And the filter captions don't match the CGBlendMode names. Granted, "Addition" might be a better name than "Plus Lighter", but at least in my case it'd be better to have the names the same. Some of these comments apply to the other filter families as well; it just happens that I'm playing with the composites. Oh, and not that I'm using it, but it'd be nice to be able to animate the Transition filters.