> I have one more question not directly related to this topic. Is there > any way to adjust *"robustness" of shape recognition*? My "straight > lines" are almost always get translated into "lines", it is a bit harder > with "circles", and I only once was able to draw a square that was > recognized as a "square". > > What are the rules that I have to follow to maximize quality of > recognition? I couldn't find any parameter in configuration file, > responsible for that, but I assume there must be something in the source > code.
Indeed there are some parameters in the source code, they are in src/xo-shapes.h They didn't make it into the config file because it is not clear to me which ones are most relevant for users to customize, and there are too many. For circles, you'd tinker with CIRCLE_MIN_DET and CIRCLE_MAX_SCORE -- decrease the first one a bit (it's on a scale from 0 to 1, with 1 only allowing perfect circles and 0 allowing any shape), increase the second one a bit (the scale there is 0 to infinity, but 1 would already catch most non-crazy shapes). For rectangles, you can try to tinker with the two RECTANGLE_... parameters, but the main obstacle in practice is that to recognize a rectangle, you have to have a stroke that is composed of four pieces that get recognized as lines -- so if you round your corners, the pieces won't pass the line recognition test -- and increasing tolerance for lines leads to too many things being mistakenly recognized as lines. The main trick to get rectangles recognized is that you don't have to draw them all in one go. If you draw the four sides successively with one pen stroke each, and each separately gets recognized as a line and the lines fit together, the four sides will get combined into a rectangle. (However, you're not allowed to undo or erase partway through the drawing process, of course). The sides must be drawn in order around the rectangle (clockwise or counterclockwise), but each individual side can be drawn forward or backwards. (So: usually I draw the top edge left-to-right, then the right edge downwards, then the bottom edge left-to-right, then the left edge downwards, and I find that recognition is a lot better this way). (In principle you can also do 2 edges first, then the 2 others, going around the rectangle, or any other such combination.) Denis ------------------------------------------------------------------------------ _______________________________________________ Xournal-devel mailing list Xournal-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xournal-devel
