watermarking medical image 3d

Hello, can any one help me to with a malab code that help me watermarking a medical image with 3 dimensions (3d) ana thanks

[Peter Eze]

Actually I am interested in this too. However, I think we need to treat 3-D medical image as several 2-D slices. We might just replicate the method used for 3-D. I have not written actual codes for 3-D.

[Walter Roberson]

Peter Eze,

We have to ask again what the real purpose is? What problem is attempting to be solved?

Answer 1

[Walter Roberson]

I would be worried about the watermark affecting the diagnostic quality of the image.

The people who proved that JPEG could be used acceptable for bone x-rays had to go through a series of blind tests with highly-skilled x-ray image readers in order to prove that there was a safe level of lossy image compression for their purposes. Without those concerted peer-reviewed studies, lossy JPEG would still be banned for clinical use.

What is the purpose of watermarking a medical image when you could instead watermark the DICOM headers?

[Jan]

The rule for handling medical images is clear: Do not touch any bit. Even the rounding errors of the _lossless_ JPEG compression at 100% quality is deprecated. +1

[Image Analyst]

That contradicts what Walter said. Not sure who is right. Maybe it depends on the jurisdiction.

[Walter Roberson]

Reference:

Quality assessment of DSA, ultrasound and CT digital images compressed with the JPEG protocol. Demetrios Okkalides and Stavros Efremides. Phys. Med. Bio. 39 (1994) 1407-1421

Answer 2

[Stephen]

Do you mean the image is several 2-d slices or the actual composite into voxels? either way, I imagine you'd have to alter the intensity values to create your watermark somewhere in the background of the image. Try drawing something in mspaint or have your logo and creating a binary image from that with the same dimension as your image, then directly add it to the existing intensity data and scale it until it reasonably appears. There's probably something out there that does this for you though. good luck

Answer 3

[slama najla]

i want to apply an dwt3 then the dct3 and embedding two watermarks in th feature vector ,but i havn't any idea concerning the code,please help me especially with dct 3 matlab code.

[Image Analyst]

But you didn't answer Walter's question of "Why?" For example, do you just want to burn a logo into some corner of the image? Or do you want to try to secretly hide some ID in the image so you can see if someone "stole" it and posted it somewhere out there in cyberspace? A visible watermark such as logos (like you see burned into images on stock photography web sites) uses different technology than steganography where the intent is to hide the logo or identifying image. Watermarking basically "ruins" the image by burning another picture into it while the point of steganography is to remains hidden and invisible (the exact opposite of watermarking's intent). At least that's how I see it, but it's not my field so what do I know. Besides that I don't see how a watermark would work in a 3D image since when you take any projection (to form a 2D image for display) the watermark will look different. You'd only be able to see the 3D watermark it if you used a 3D volumetric visualization program, which MATLAB is not.

[slama najla]

i want to apply the watermarking to protect the 3d data to any attaq,so iwork in the robustness of the watermarked dat to compression,rotation, cropping,translation...but i can't insert an image (64*64)on a data(128-128*28)using dwt-dct,the problem that how can i choose the coefficients for embed the mark (the selection i want to do it by a threshold or a chaotic generator)any one can help me please?

[Image Analyst]

I'd suggest you search the vision bibliography (http://iris.usc.edu/Vision-Notes/bibliography/contents.html) or internet for watermarking. I could be wrong but I don't think theft of medical images is prevalent, such that you need to watermark images and then try to get digital copies of your stolen images and try to see if they have your watermark in them. First of all, where is the profit motive for people to steal your images? How will they make money off them? Secondly using/stealing medical images without permission of the patient and medical practice violates privacy laws (HIPPA in the US) and there are substantial penalties. Thirdly, image owners should have safeguards in place to prevent theft or unauthorized use of images. So with all that, can you tell me how much of a problem this is?