Not that sorting is really about images
. Still, there are plenty of examples of pixel shaders being used for image manipulation. Apple has its Core-Image which allow photoshop-like applications to manipulate images through pixel shaders.
Another application that uses shaders (which you can write yourself!) is the open source Media Player Classic.
This example shows embossing done in realtime on a 30fps video stream without any extra CPU usage! You could probably do lots of things like noise-reduction, edge enhancement, sharpening, etc with shaders too. It is what the GPU was meant to do =).
Shader code: Emboss:
Code: Select all
sampler s0 : register(s0);
float4 p0 : register(c0);
float4 p1 : register(c1);
#define width (p0[0])
#define height (p0[1])
#define counter (p0[2])
#define clock (p0[3])
#define one_over_width (p1[0])
#define one_over_height (p1[1])
#define PI acos(-1)
float4 main(float2 tex : TEXCOORD0) : COLOR
{
float dx = 1/width;
float dy = 1/height;
float4 c1 = tex2D(s0, tex + float2(-dx,-dy));
float4 c2 = tex2D(s0, tex + float2(0,-dy));
float4 c4 = tex2D(s0, tex + float2(-dx,0));
float4 c6 = tex2D(s0, tex + float2(dx,0));
float4 c8 = tex2D(s0, tex + float2(0,dy));
float4 c9 = tex2D(s0, tex + float2(dx,dy));
float4 c0 = (-c1-c2-c4+c6+c8+c9);
c0 = (c0.r+c0.g+c0.b)/3 + 0.5;
return c0;
}
Shader code: Contour:
Code: Select all
sampler s0 : register(s0);
float4 p0 : register(c0);
float4 p1 : register(c1);
#define width (p0[0])
#define height (p0[1])
#define counter (p0[2])
#define clock (p0[3])
#define one_over_width (p1[0])
#define one_over_height (p1[1])
#define PI acos(-1)
float4 main(float2 tex : TEXCOORD0) : COLOR
{
float dx = 4/width;
float dy = 4/height;
float4 c2 = tex2D(s0, tex + float2(0,-dy));
float4 c4 = tex2D(s0, tex + float2(-dx,0));
float4 c5 = tex2D(s0, tex + float2(0,0));
float4 c6 = tex2D(s0, tex + float2(dx,0));
float4 c8 = tex2D(s0, tex + float2(0,dy));
float4 c0 = (-c2-c4+c5*4-c6-c8);
if(length(c0) < 1.0) c0 = float4(0,0,0,0);
else c0 = float4(1,1,1,0);
return c0;
}
