Influence of Unequilateral Apertures of the "Trunced Pyramid" and "Double Pyramid" Laplacian Digital Filters on the Accuracy of Television Measuring Systems

In the modern world, digital image processing requires increasing the speed of the processing methods and algorithms used. One way to improve performance is to transform spatial filters into filters with a recursively separable form of implementation. The recursion property implies the use of previous output values of a function to form the current sample. The property of separability is understood as division into processing by column and row of a matrix of digital image values. The transformation of spatial filters consists of changing the aperture of the masks into a non-orthogonal (non-equilateral) form, which reduces the number of computational operations and speeds up the processing process, while maintaining its efficiency. The paper presents a description of the non-equilateral apertures of the previously developed “truncated pyramid” and “double pyramid”Laplacian digital filters. For non-equilateral apertures, results were obtained for the first time on their use for television measuring systems. From which it can be seen that a “truncated pyramid” Laplacian filter with non-equilateral processing apertures is recommended for use in TIS, since it increases the efficiency of measuring the range to objects of interest while reducing processing time. Based on the results of processing with modified filters, sets of processed images were obtained for each of the 10 original images. For each set of processed images, measurements of the peak signal-to-noise ratio, standard deviation and selection of the optimal central coefficient of the filter mask were carried out, for subsequent assessment of the effectiveness of processing with modified filters. The assessment of the influence of recursively separable “truncated pyramid” and “double pyramid” Laplacian filters with non-equilateral aperture masks on the accuracy of television measurement systems consisted of considering their influence on measuring the distance (from the camera) to the object of interest in the image, when – control of processing time. Based on the evaluation results, we can conclude that by using pre-processing of images with modified digital filters, the accuracy of measuring the distance from the camera to the measurement object is improved, while reducing processing time.