00758naa#a2200193#i#450# EN\\bibl\71479 20241122174253.5 2072-9502 20231109b2023####ek#y0engy0150####ca RU Investigation of the gain effect on the distortion degree and the efficiency of extracting a digital watermark on full-color images by the discrete transformations method Journal article Astrakhan Astrakhan State Technical University 2023 7 с. Journal article local Обработка изображений. 004.932 Sibikina Irina Vyacheslavovna Daviduk Nadezhda Valerievna Savoskin Igor Aleksandrovich vestnik.astu.org