Table 1 Summarization of the proposed method

Input: A suspicious image.

Input parameters: Size of a block from the image.

Output: Estimated modified hue angle H _F .

 1) Choose the image block located at the center of the given image.

  A. Set H = 0.

  B. Compute the color differences using (8), (9), (10), and (11).

  C. Perform the wavelet transform.

  D. Calculate the two variances for the highest frequency subbands using (12) and (13)

  E. Compute V _E (H) using (15).

  F. Increase the hue value by ΔH (we use ΔH = 5) for the selected image block,

   if H > 360, then go to 2); otherwise, go to B.

 2) Find the minimum hue value H _r using (17)

 3) Execute the AIVC algorithm for H _r and H _r  + 180^°.

 4) Obtain H _F by taking the minimum of H _r and H _r  + 180^°.