Grzegorz Kossakowski <[EMAIL PROTECTED]> writes: > [EMAIL PROTECTED] pisze: >> The imageop block is quite useful for image operations, much more so >> than the imagereader in the core. It would be nice if it could be >> released. >> >> However there seems to be some problems with rotation code. >> I mostly managed to get lots of black areas, and spurious image >> fragments in the rotated image. >> >> I had a look at the cocde and its not obvious what a rotation should >> do, which I think is the root cause of the problem. (that is, what >> should be the bounding box, where should the anchor for rotation be etc) >> >> I propose hiding the general rotation operator, and implementing a >> rotate-at-right-angle operator. > > Can you explain how this operator would work? I don't have much experience > with image processing so I may miss something obvious.
I tried to find a name that would be obvious, I dont know if I suceeded. Another name might be "order-4-rotate". right-angle-rotate simply means rotate by 90, 180, or 270 degrees, and dont accept intermediary values. The current rotate operator is supposed to be able to do this, but somehow fails. > >> This special case is IMHO the most useful type of rotation, its >> obvious how it should work, and could be more easily implemented and >> perhaps optimized. >> >> I can implement this if the list decides this is a good idea. (I will >> probably anyway for my own needs). The general rotation operator could >> be tackledd later, but wouldnt be necessary for release. > > Feel free to submit patch that will include this new operator, > adjusted sample and test case. I'm very happy that you want to spend > some time on imageop block and make it ready for a release. I will try next week, but I will be on a 3g modem, so image trial-and-terror will be somewhat slow. I already have something somewhat working, but need to test all the cases. > > -- > Grzegorz Kossakowski > http://reflectingonthevicissitudes.wordpress.com/ -- Joakim Verona
