4 ms·

Just out of curiosity, how did you overcome slow HTML5 canvas' getImageData and pixel reading from an image affected by CORS (tainted canvas)?

• skavish 12y ago
  i am interested in this as well. the app is awesome btw!
• patrick73 12y ago
  with WebGL?
  • bitL 12y ago
    WebGL textures suffer from the same problem as shaders can be used to extract data. WebGL is hence using CORS as well. Do you say the performance penalty in WebGL is non-existing contrary to canvas?
    • patrick73 12y ago
      what data do you want to extract?, all postprocessing effects are made with GLSL shaders, you don't process data with javascript algorithms.
      • bitL 12y ago
        Just the call on getImageData to extract texture and read all pixels from an image can take 15s if CORS is in the play...
        • patrick73 12y ago
          you don't call getImageData to extract a texture data. You load the image, make a texture of it, and then apply all postprocessing effects with a WebGL shader.
          • bitL 12y ago
            OK, thanks for the hint! I'll try to play with CORSed image texture binding to see what the performance is.