How to generate an histogram using iOS GPUImage?
问题 Working on https://github.com/luisespinoza/LEColorPicker project, I am trying to generate an histogram UIImage from an arbitrary input UIImage using the project GPUImage (https://github.com/BradLarson/GPUImage). The current code that I'm using is the following: - (NSDictionary*)dictionaryWithColorsPickedFromImage:(UIImage *)image { GPUImageFilter *filter = [[GPUImageHistogramFilter alloc] initWithHistogramType:kGPUImageHistogramRGB]; UIImage *filteredImage = [filter imageByFilteringImage