Accuracy improvement of histogram-based image filtering

We propose a method for improving the accuracy of histogram-based image filtering. With this method, we define a histogram called intensity-stacked histogram. An image histogram generally consists of a frequency (number of pixels) for each bin. On the other hand, intensity-stacked histogram stores the sum of intensity values for each bin. The intensity-stacked histogram can be calculated in constant time similar to a standard histogram. We apply the intensity-stacked histogram to histogram-based image algorithms for median and bilateral filters. The histogram-based image filter with the intensity-stacked histogram works effectively when using a few bins. We confirmed that the accuracy of histogram-based image filters using intensity-stacked histogram is higher than that using standard histogram.