how to calculate DWT of an image

im using forgery detection approach using DWT. and the algorithm says after converting the image into gray scale calculate DWT transform of the image. but i dont know DWT. So kinda stuck in this step. if any one knows kindly post. Thank You.

Answer 1

[Walter Roberson]

Have you considered using the dwt() function?

[Prajakta Shende]

im suppose to calculate dwt for each block and store it in another array. with every row containing containing coefficients of the dwt.

can u please help me with that?

Answer 2

[Wayne King]

Hi Prajakta, you want to use dwt2() or wavedec2(). However, I think you need to clarify what you mean by "for each block".

Are you saying you have a NxN image, and you want to subdivide that image before obtain the DWT?

[Prajakta Shende]

okay which function to use i really don't know :$ :(

and yeah i mean the exact thing that u wrote. dividing an nxn sized image into overlapping blocks.