A method of images contrast enhancement under conditions of the Earth survey from space

摘要

Subject of Research. A method is proposed for the contrast enhancement of the Earth's surface images obtained by airborne optoelectronic complexes of space remote sensing systems. The relevance of the proposed method is confirmed by the results of contrast estimation for space images obtained by modern recording equipment and the results of the contrast calculation for modeled survey conditions. Method. The method is based on the idea of combining different exposure space images. This combination gives the possibility to get the resulting snapshot with an extended dynamic range of brightness. Such picture has a high contrast in the field of dark and light halftones and displays the details of the observed objects better. Main Results. The contrast of the image obtained when selecting the survey parameters by traditional method is estimated. It is concluded that the quality of the images obtained from space is currently limited, since the parameters of the onboard optoelectronic complex do not provide taking into account a larger number of objects with different optical characteristics that are within the capture area of the recording equipment. On the basis of research, an approach to images contrast enhancement is proposed, the essence of which is to expand the dynamic range of brightness and, as a result, to increase the contrast of the images obtained. Practical Relevance. The proposed method for the Earth's remote sensing data processing gives the possibility to obtain images of objects located on the Earth's surface in any light conditions suitable for interpretation. This fact will improve the accuracy of information provision when performing work survey support and mapping areas