The files Frid2_Emb is the watermark embedding algorithm
and frid2_dec is the watermarking decoding algorithm .
My project is on digital image watermarking.We will embed some text information in the image and get the output as an image file for Frid2_Emb program and we ill jpeg compress or add noise or do some attack to the image by photoshop or some other means
and give that attacked image as an input to the other program ( frid2_dec ).
here the output will be the image and text file saperately and we check how much text is received coerrectly after compression or some attack.
we will not get the same input completely at the output of the decoding problem. first e tried to improve the output by adding some coding techniques but couldnt succeed.So now what i want to do is, for every attack ,according to attacking factor we have some limit for embedding data.
say for example if we want to compress the image upto quality 50 we can embeded only 58 bits of data.if we cross that limit we will not get complete dat at the receiver side.so we need to write a program which will divide the messege into the equal parts and embed into different copies of image . the program will have the following flow
say Lq is the length of messege which can be embedded for a particular quality factor it will vary (example for jpeg40 -40bits jpeg 50 -58bits and so on.....)
and ml be the messege length which we want to embed
and if ml > lq
then q= ml/lq
tt= ceil(q)
and for i=1 i++ i=tt
block(i)=ml( 1 to lq)
like it should divide the messege into some blocks equal
please let me know if u have any questions.please see if you have any friends in image processing felid for them it will be much easier.