HisDataTJ: ImageJ Plugin for Global Thresholding with Application in Bread Porosity Evaluation

It is developed a plugin for ImageJ that performs global thresholding through four innovative thresholding algorithms, which are designed last five years. These algorithms are HisMedian, SubMedian-1, SubMedian-2, and HisAnalysis. The algorithm SubMedian-2 uses secondary median value in the sub-histogram as a threshold and it is applied for white bread porosity evaluation. The algorithm HisAnalysis uses as a threshold a color with maximal frequency in image histogram and it is applied for brown bread porosity evaluation. It is implemented also an algorithm (MedHASM-2) that combines methods for threshold finding which are used by HisAnalysis and SubMedian-2 algorithms. This paper presents a research of possibilities for application of global thresholding algorithms in wheat bread type "Dobrudzha" porosity evaluation. Four samples of different brands of wheat bread are used for experiments. The porosity of tested samples is measured through physicochemical analysis. The results are compared with results of image processing through correlation analysis. The highest correlation coefficients are calculated for results of thresholding with algorithms HisAnalysis and MedHASM-2. Based on the results of statistical data processing it is proposed an equation for calculation of the bread porosity using the ratio of white pixels to all in binary images. The average error for bread porosity calculated with the proposed equation is about 1% using the algorithm MedHASM-2 and about 3% using the algorithm HisAnalysis.