Processing multi-megapixel images in CPU JavaScript causes noticeable UI jank and main-thread blocking. By uploading image pixel buffers to GPU video memory as 2D textures, developers can execute parallel GLSL fragment shaders to achieve 60+ FPS real-time color grading, Gaussian blurs, and Sobel edge detection.
1. WebGL 2.0 Texture Binding Architecture
To execute fragment shader passes, we render a full-screen viewport quad using two triangles and map the source texture coordinate space (UVs from 0.0 to 1.0).