/// <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 Blur(GaussianBlurQuality quality, Texture inputTex,
RenderTextureFormat outFormat = RenderTextureFormat.ARGB32,
TextureWrapMode wrapMode = TextureWrapMode.Clamp)
{
var outTex = new RenderTexture(inputTex.width, inputTex.height, 0, outFormat,
RenderTextureReadWrite.Linear);
outTex.filterMode = FilterMode.Bilinear;
outTex.wrapMode = wrapMode;
Blur(quality, inputTex, outTex, wrapMode);
return(outTex);
}
/// <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);
}
public static void Blur(GaussianBlurQuality quality,
Texture input, RenderTexture output,
TextureWrapMode wrapMode = TextureWrapMode.Clamp)
{
//Allocate an intermediate texture for the two-pass blur.
var tempTex = RenderTexture.GetTemporary(output.width, output.height, 0, output.format,
RenderTextureReadWrite.Linear);
tempTex.filterMode = FilterMode.Bilinear;
tempTex.wrapMode = wrapMode;
//Do the blur.
Passes pass1, pass2;
switch (quality)
{
case GaussianBlurQuality.Low:
pass1 = Passes.Gaussian5_P1;
pass2 = Passes.Gaussian5_P2;
break;
case GaussianBlurQuality.High:
pass1 = Passes.Gaussian9_P1;
pass2 = Passes.Gaussian9_P2;
break;
default: throw new NotImplementedException(quality.ToString());
}
var mat = UberFilterMat;
Graphics.Blit(input, tempTex, mat, (int)pass1);
Graphics.Blit(tempTex, output, mat, (int)pass2);
//Clean up.
RenderTexture.ReleaseTemporary(tempTex);
}
