/// <summary>
/// Performs the Canny edge detection algorithm given a color image.
/// The output is a texture that stores edge gradients in Red-Green
/// and edge strengths in Blue.
/// Note that edge strength is equal to the length of the edge gradient.
/// </summary>
public static void FullCannyEdgeFilter(
Texture inputTex, RenderTexture outputTex,
GaussianBlurQuality blurQuality, GreyscaleTypes greyscaleMode, EdgeFilters edgeFilter,
float weakEdgeThreshold, float strongEdgeThreshold,
TextureWrapMode samplingWrapMode = TextureWrapMode.Clamp)
{
RenderTexture out_gaussian = RenderTexture.GetTemporary(
inputTex.width, inputTex.height, 0,
RenderTextureFormat.ARGB32, RenderTextureReadWrite.Linear),
out_greyscale = RenderTexture.GetTemporary(
outputTex.width, outputTex.height, 0,
RenderTextureFormat.RInt, RenderTextureReadWrite.Linear),
out_edgeDetect = RenderTexture.GetTemporary(
outputTex.width, outputTex.height, 0,
RenderTextureFormat.RGFloat, RenderTextureReadWrite.Linear);
out_gaussian.filterMode = FilterMode.Point;
out_gaussian.wrapMode = samplingWrapMode;
out_greyscale.filterMode = FilterMode.Point;
out_greyscale.wrapMode = samplingWrapMode;
out_edgeDetect.filterMode = FilterMode.Point;
out_edgeDetect.wrapMode = samplingWrapMode;
Blur(blurQuality, inputTex, out_gaussian, samplingWrapMode);
Greyscale(greyscaleMode, out_gaussian, out_greyscale);
EdgeFilter(edgeFilter, out_greyscale, out_edgeDetect, samplingWrapMode);
CannyEdgeFilter(out_edgeDetect, outputTex,
weakEdgeThreshold, strongEdgeThreshold,
samplingWrapMode);
RenderTexture.ReleaseTemporary(out_edgeDetect);
RenderTexture.ReleaseTemporary(out_greyscale);
RenderTexture.ReleaseTemporary(out_gaussian);
}
public static RenderTexture Greyscale(GreyscaleTypes type, Texture inputTex,
RenderTextureFormat outFormat = RenderTextureFormat.RInt)
{
var outTex = new RenderTexture(inputTex.width, inputTex.height, 0, outFormat,
RenderTextureReadWrite.Linear);
outTex.filterMode = FilterMode.Point;
Greyscale(type, inputTex, outTex);
return(outTex);
}
public static void Greyscale(GreyscaleTypes type, Texture input, RenderTexture output)
{
//Get the correct pass to use in the uber filter shader.
Passes pass;
switch (type)
{
case GreyscaleTypes.PreserveLuminance:
pass = Passes.LuminanceGreyscale;
break;
default: throw new NotImplementedException(type.ToString());
}
//Do the filter.
var mat = UberFilterMat;
Graphics.Blit(input, output, mat, (int)pass);
}
/// <summary>
/// Performs the Canny edge detection algorithm given a color image.
/// </summary>
public static RenderTexture FullCannyEdgeFilter(
Texture inputTex,
GaussianBlurQuality blurQuality, GreyscaleTypes greyscaleMode, EdgeFilters edgeFilter,
float weakEdgeThreshold, float strongEdgeThreshold,
TextureWrapMode samplingWrapMode = TextureWrapMode.Clamp,
RenderTextureFormat outFormat = RenderTextureFormat.ARGBFloat)
{
var outTex = new RenderTexture(inputTex.width, inputTex.height, 0,
outFormat, RenderTextureReadWrite.Linear);
outTex.filterMode = FilterMode.Point;
outTex.wrapMode = samplingWrapMode;
FullCannyEdgeFilter(inputTex, outTex,
blurQuality, greyscaleMode, edgeFilter,
weakEdgeThreshold, strongEdgeThreshold,
samplingWrapMode);
return(outTex);
}
