mohammadimtiazz/histogram

it presents source code for measuring histogram from images and plot them in cv Window!

histogram

'histExample' presents source code for measuring histogram from images and plot them in cv Window! It can also compare two hostogram and meseaure how much similar/disimlar they are!

Helpful links: http://www.aishack.in/tutorials/drawing-histograms-opencv/

http://karthicknopencv.blogspot.com/2010/04/getting-histogram-for-given-grayscale.html

http://www.programming-techniques.com/2013/01/histogram-equalization-using-c-image.html

'compHistExmp' presents source code for comparing two histogram based on correlation function, CHI-SQUARE algorithm, interscetion and Bhattacharyya distance. All thses have been done using openCV lib. OpenCV histogram comparison link is given below: http://docs.opencv.org/2.4/doc/tutorials/imgproc/histograms/histogram_comparison/histogram_comparison.html

Some Important info about Chi-Square algorithm https://www.researchgate.net/post/What_is_chi-squared_distance_I_need_help_with_the_source_code

https://stats.stackexchange.com/questions/184101/comparing-two-histograms-using-chi-square-distance

http://www.itl.nist.gov/div898/handbook/eda/section3/eda35f.htm

'compHistExmp2' presents the similar histogram comparison program as same as 'compHistExmp'. The main difference is that all the functions to excute the algorithms have been made from scratch. No openCV lib has been used. The following functions are stated in the 'compHistExmp2' file...

imhist -> for measuring histogram

m2_chiSquare -> measuring quadric chi square value detail of quadric chi square can be found here: https://stats.stackexchange.com/questions/184101/comparing-two-histograms-using-chi-square-distance

m1_chiSquare -> measuring chi-square value (regular) for detail: https://stats.stackexchange.com/questions/184101/comparing-two-histograms-using-chi-square-distance

normHistUsingTrapz -> Normalization using Trapezoidal numerical integration for details: https://stackoverflow.com/questions/5320677/how-to-normalize-a-histogram-in-matlab Trapezoidal: https://www.mathworks.com/help/matlab/ref/trapz.html

normHistUsingPdf -> Normalization using PDF for details: https://stackoverflow.com/questions/5320677/how-to-normalize-a-histogram-in-matlab

intersection-> Measure intersection correlation-> measure correlation bhattacharyyaDis->Measure Bhattacharyya distance For details of these three: http://docs.opencv.org/2.4/doc/tutorials/imgproc/histograms/histogram_comparison/histogram_comparison.html

"histStatistics" -> can measure MEAN, MODE and PERCENTILE of a single plane of color image or 2 dimensional gray image. Here the percentile feature measure energy of pixel >= 200. We can change this value or move that value in a upper and lower range too.