Image Warping - Bulge Effect Algorithm

Question

Can any point to image warping algorithms? Specifically for bulge effect?

Answer 1

GLSL code version:

uniform sampler2D tex;

void main()
{
 vec2 cen = vec2(0.5,0.5) - gl_TexCoord[0].xy;
 vec2 mcen = - // delete minus for implosion effect
      0.07*log(length(cen))*normalize(cen);
 gl_FragColor = texture2D(tex, gl_TexCoord[0].xy+mcen);
}

original:

explosion:

implosion:

cheers!