security analysis of image using UACI and NPCR for encrypted image

4 次查看（过去 30 天）
faiz
faiz 2016-10-3
评论： yahia 2023-4-15
i am trying to find the UACI value for two encrypted images, having one pixel value changed in original plain image.i get value greater than 0.4, on the other hand in most of the papers i read having 0.334 or 0.34 maximum value for UACI. CAN ANYONE EXPLAIN THE UACI and NPCR ?what is the maximum achievable value of UACI?
npcr_score = sum( double( img_a(:) ~= img_b(:) ) ) / num_of_pix;
uaci_score = sum( abs( img_a(:) - img_b(:) ) ) / num_of_pix / largest_allowed_val;
i am using the above matlab code for finding NPCR and UACI. img_a and img_b both are encrypted image having one pixel value changed in original image.

请先登录，再回答此问题。

回答（1 个）

Walter Roberson
Walter Roberson 2016-10-3
uaci_score = sum( abs( double(img_a(:)) - double(img_b(:)) ) ) / num_of_pix / largest_allowed_val;
  3 个评论
显示 1更早的评论

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Programming 的更多信息

标签

产品

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by