OpenGL image processing shaders

Simple vertex & fragment OpenGL shaders for very basic image processing features (convolution & point transform)

Files

post_vertex.glsl
post_fragment.glsl

Usage

These shaders should be used for postprocessing
Vertex shader contains all the necessary data to draw triangle spanning the screen so you just need to have an empty vao and draw with glDrawArrays(GL_TRIANGLES, 0, 3);

Example kernels

You can use whatever kernel you need && change its dimensions depending on your needs.

Gauss 5x5 kernel (multiplier 1.0/256.0):
{{ 1, 4, 6, 4, 1 },
{ 4, 16, 24, 16, 4 },
{ 6, 24, 36, 24, 6 },
{ 4, 16, 24, 16, 4 },
{ 1, 4, 6, 4, 1 }}

Mean filter 3x3 (multiplier 1.0/9.0):
{{ 1, 1, 1},
{ 1, 1, 1},
{ 1, 1, 1}}

Laplace edge detection 3x3 kernel (multiplier 1.0):
{{ 0, -1, 0},
{ -1, 4, -1},
{ 0, -1, 0}}