|
|
|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [WM]: Re: wavelet based watermarked
I think the robustness of your algorithm only depends on the alpha value if you're using single pseudo stream in the size of row*col
of the original image.
In this case, if you want to increase the robustness, you should increase alpha value. But, as you know, bigger alpha value also
increases the visual distortion of your image.
You can also think about the way of generation of pseudo sequence. But, in my opinion, the robustness won't be changed a lot.
MR. Min-Su KIM :)
----- Original Message -----
From: "bo zambo" <bo_me_bo@yahoo.com>
To: <watermarking@watermarkingworld.org>
Sent: Wednesday, September 07, 2005 12:37 PM
Subject: Re: [WM]: Re: wavelet based watermarked
>
> thanks Mr/Ms Min-Su KIM
> I havatermarked
>
> thanks Mr/Ms Min-Su KIM
>e done what you told and the max value of alpha to have watermark image as same as the original visually is only 0.1, Is it
> ok? is it to small for robustness? is it because I use db filter for dwt? or it because the pseudorandom binary sequence that I
use?
> I generate it just like that, no rules and other just a sequence of 1 and -1. Do I have to use the pseudorandom binary sequence
with
> zero mean and variance 1? thank you very much!
>
> Bo
>
> --- Min-Su KIM <speedyminsu@gmail.com> wrote:
>
>> after forward WT, did you insert a bit like THIS?
>> W = W + M ?
>> ,where W is detail coefficient, M is your random bits.
>>
>> and if you did so, maybe, it wasrandom bits.
>>
>> too big to be invisible.
>>
>> Try like THIS,
>>
>> W = W + alpha * M,
>>
>> , where 0.0 < alpha <1.0
>>
>> you can control the strength of your watermark mor
>>e invisible with
>> alpha.
>>
>> or you can also trynvisible with
>> alpha.
>>
> like THIS,
>>
>> W = W + alpha * M * W,
>>
>> , wke THIS,
>>
>> W = W + alpha * M * W,
>>here 0.0 < alpha <1.0.
>>
>> You can see our BIBLE booe 0.0 < alpha <1.0.
>>
>k, DIGITAL WATERMARKING from the the COX, the
>> MILLER, and the BLOOM . :)
>>
>> ----- Original Message ----nd the BLOOM . :)
>>-
>> From: "bo zambo" <bo_me_bo@yahoo.com>
>> To: <watermarking@watermarkingworld.org>
>> Sent: Wednesday, August 24, 2005 5:41 PM
>> Subject: [WM]: wavelet based watermarked
>>
>>
>> > dear watermarkers
>> >
>> > I'rked
>>
>>
>> > dear watermarkers
>> >
>> >m working on a wavelet based watermarked...I'm
>> really new in this field and I have lot to ask...
>> > I try a simple wavelet based watermarked just
>> decomposed themple wavelet based watermarked just
>> image and change the details coeffecients of the lowest
>> level by adding
>> > it with 1 or -1 (randomly) aft> level by adding
>>er that inverse DWT,
>> the problem is...the watermarkedthat inverse DWT,
>> image is not perceptual
>> invisibility...can
>> > anage is not perceptual
>> invisibility...can
>> >tone tell me why and rceptual invisibility...can how to fix this.
>> >I follow the step from some papers
>> butthis.
>> > the result is not the same. Am I miss some step?
>> Ok
>> > thanks. please don't laugh,,I really new in these
>> field,,,ok you can laugh but please answer my question.
>> >
>> > regau can laugh but please answer my quest>> >
>>ion.
>> >rds
>> > Bo
>
______________________________________________________________________________
Watermarking Mailing List - http://www.watermarkingworld.org/ml.html
To unsubscribe send email to "majordomo@watermarkingworld.org" with
"unsubscribe watermarking YOURMAIL" in the body.
______________________________________________________________________________
|
