GPUImageCannyEdgeDetectionFilter.h

#import "GPUImageFilterGroup.h"

@class GPUImageGaussianBlurFilter;
@class GPUImageThresholdEdgeDetection;
@class GPUImageSketchFilter;

@interface GPUImageCannyEdgeDetectionFilter : GPUImageFilterGroup
{
    GPUImageGaussianBlurFilter *blurFilter;
    GPUImageThresholdEdgeDetection *edgeDetectionFilter;
//    GPUImageSketchFilter *edgeDetectionFilter;
}

// The image width and height factors tweak the appearance of the edges. By default, they match the inverse of the filter size in pixels
@property(readwrite, nonatomic) CGFloat texelWidth; 
@property(readwrite, nonatomic) CGFloat texelHeight; 

// A multiplier for the blur size, ranging from 0.0 on up, with a default of 1.0
@property (readwrite, nonatomic) CGFloat blurSize;

// Any edge above this threshold will be black, and anything below white. Ranges from 0.0 to 1.0, with 0.5 as the default
@property(readwrite, nonatomic) CGFloat threshold; 

@end