Improved bwmorph Function in the MATLAB Image Processing Toolbox for Fast Computation of Repeated Morphological Dilations and Erosions

In applications, morphological operations such as dilation and erosion are executed consecutively for a number of times. Direct use of the existing MATLAB functions for this task is time consuming. To accelerate such repeated dilations and erosions, improving measures are proposed. Binary image pixels are categorized into open feature pixels, closed feature pixels, and background pixels. By introducing a status matrix storing the category of each pixel and manipulating an open pixel list, each single operation of the repeated dilations or erosions is restricted on those pixels where the operation has real effects, and thus eliminate redundant and unnecessary computations. Experimental results show that the proposed approach is effective, and the repeated operations are significantly accelerated.