Correction of optical errors in the images of visualized optically transparent polymeric foils

The contribution treats the topic of analysis of deformations sources of images of visualized transparent polymeric foils by the schlieren methods and by the methods of image processing. The brightness deformations are rectifiable by means of schlieren apparatus setting and by the methods of image processing. A new method of brightness deformation correction by the linear regression model is presented. The method is completed by the image correction of foil based on the equalizing grayscale local mean values to the global mean value of the image. The contribution of described correction is illustrated by improving of properties of signatures calculated from foils images by the statistical methods of foils classification.