Hi folks, I have just committed a new LCD rendering technique, which has been in the Harmony branch for some time now.
Basically, forget tripling the resolution, forget LCD low-pass filtering. Instead render 3 grayscale bitmaps by shifting the outline by 1/3 pixel and combine the results. You are done without any additional filtering. The result is supposed to be identical to the light filtering using the ClearType technique I have been soliciting feedback for a few month now specifically regarding the Clear Type patents. Some folks pointed out this specific paragraph: "The color values are independently generated for each of the red, green, and blue pixel sub-components based on different portions of the image, rather than the color values for the entire pixel being generated based on a single sample or the same portion of the image." This is indeed fundamental to ClearType, where each color channel gets coverage information from completely *different* (distinct, non-overlapping) portions of the glyph. It is too bad that it also results in *unequal* coverage of each channel grid (aka color fringes) and filtering becomes necessary to equalize the channels. So, Harmony is equalized to begin with because shifting does not change the integrated channel coverage. As for the patents, the adjacent channels get coverage from parts of glyph that have 2/3 overlap (truly, more similar than different). This is how I would argue that this technique is substantially not ClearType. What do you think? Alexei _______________________________________________ Freetype-devel mailing list Freetype-devel@nongnu.org https://lists.nongnu.org/mailman/listinfo/freetype-devel
