Frosted glass Pixel Shader

We can get frosted glass effect by shifting pixel location with pseudo-random vector, such as after shift respective pattern emerges. Frosted glass GLSL pixel shader code:

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uniform sampler2D tex;

float rand(vec2 co){
  return fract(sin(dot(co.xy ,vec2(92.,80.))) + 
                  cos(dot(co.xy ,vec2(41.,62.))) * 5.1);
}

void main()
{
  vec2 rnd = vec2(rand(gl_TexCoord[0].xy),rand(gl_TexCoord[0].xy));
  gl_FragColor = texture2D(tex, gl_TexCoord[0].xy+rnd*0.05);
}

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Original image

and processed with frosted glass filter