I am doing a project in invisible Video Watermarking in Matlab. But I don't know where to start and how to do it. All I can find is visible watermark on the video. Can anyone help?
If you search for the term 'steganographic' in this context it may help - steganography is basically hiding one message in another and some of the academic and basic building block material may favour this term. Some of the video techniques will be strongly related to single image techniques also as the hidden image or watermark, or part of the watermark more commonly, is hidden in individual frames within the video.
Some examples in the MathLab domain:
https://www.mathworks.com/matlabcentral/fileexchange/41326-steganography-using-lsb-substitution?requestedDomain=true
https://sites.google.com/site/cs534steganographyproject/home/matlab-code-and-examples
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I'm doing an object recognition project and would like to actively see objects being recognized in a video feed. This requires the object be boxed around in the live feed. The box would automatically adjust in size depending on the size of the object.
Is this possible in matlab?
Assuming you can do it for an image, just do it for every image and you have done it for the video.
If this is too slow, you may only want to calculate the box for every nth image.
In case you want a more detailed answer, please show where you get stuck.
I am working on an Iphone application.
I need to do the following: when the user clicks on the "Camera Tab" the camera open inside the view with circle overlays.
I want to apply a filtering algorithm on the camera.
I am looking for the best way to do this. Is there a library that can help?
What I am doing currently:
I am using the OpenCV Library.
I define a timer.
For each timer tick I call cvCaptureFromCam() method from the OpenCV
framework (This will capture the picture with a camera and return
it).
I apply the algorithm on the image captured.
i display the image in a UIImageView
The idea is that on each timer tick I get the image, filter it and put it in the UIImageView. If the timer tick is fast enough it will appear as continuous.
However the cvCaptureFromCam is a little slow and this whole process is taking too much memory.
Any suggestions of a better way is greatly appreciated. Thanks
Anything that's based on CPU-bound processing, such as OpenCV, is probably going to be too slow for live video filtering on current iOS devices. As I state in this answer, I highly recommend looking to OpenGL ES for this.
As mentioned by CSmith, I've written an open source framework called GPUImage for doing this style of GPU-based filtering without having to worry about the underlying OpenGL ES involved. Most of the filters in this framework can be applied to live video at 640x480 at well over the 30 FPS framerate of the iOS camera. I've been gradually adding filters with the goal of replacing all of those present in Core Image, as well as most of the image processing functions of OpenCV. If there's something I'm missing from OpenCV that you need, let me know on the issues page for the project.
Build and run the FilterShowcase example application to see a full listing of the available filters and how they perform on live video sources, and look at the SimplePhotoFilter example to see how you can apply those filters to preview video and photos taken by the camera.
I'm a noob to this forum, but wanted to give it a try.
I'm currently learning Objective-C and Cocoa; trying to build my first iPhone app.
One thing I'm working on is allowing the user to cut his/her face from an image they have taken and paste it into another image. (The idea is cut from one image and paste into another image with a spot for a face to go.)
How can this be done? I am thinking I would allow the user to just touch and drag over their face, in the shape of a rectangle, and then allow them to copy.
Thanks for the help.
Ok, nevertheless your bit arrogant style of asking, here are some guidelines about how to start: generic obj-c/iOS development (start from hello world); UIImage class; camera API; image processing algorithms, face detection algorithms. Go on gradually and do not wish to resolve all problems at once. Write first an application that simple loads an arbitrary photo and shows it to the user. Then modify it that you can crop a specified rectangular area from the image and save it into the new file. Then write an app that switches on the camera that you can take an image and save it to the disk. Then unite what you wrote that you save only a cropped area of the captured image.
When you arrive to this point, you will know much more about software development image handling. AFTER THIS you can start looking for image processing algorithms. Start also here with something simple like a trivial blur filter or similar implemented by you. If you know already a bit of image processing, search for face detection algorithms on the net. It is even possible that you will find some ready framework that includes also these features, or at least you will understand the concepts. You can even come back here to stack overflow and ask for suggestions about a good face detection algorithms, however we still prefer if you have chosen already one and have some concrete issue with it.
HI all ,what i want is to map the images.Suppose i have two images of persons,one is of fat person and another is of weak person,Now i want to match their faces ,eyes.I want to increase or decrease the face size eye size of one image according to another.As you can see in adobe photoshop you can make the face fat,make it squueze.I want to do the image manuplation in this.These types of operations i want to implement.I don't know from where to start.
Pleas guide and help me.Can i perform all this with core graphics if so then how
Any reference,tutorial address ,sample code ........appreciated.
You are probably going to have to deal with some sort of edge detection and face recognition algorithms, at the very least, if this is to be accomplished automatically. Otherwise, if the user is going to be resizing one image to match the other, this will require simple resizing operations driven by perhaps user pinch & gestures.
UPDATE:
For manual resizing:
Download the source code for the great book Cool iPhone Projects. One of the projects is called 'Touching'. This project contains code that accomplishes what you need: pinch and zoom functionality.
I want to remove watermark from a picture within my iPhone / iPad application. Is there any kind of image processing I can perform within this application to do this?
Can't be done, sorry.
The watermarked image were originally two images (the base and the watermark), which were merged together to form the result. The problem here is that the most common image formats (such as JPG, PNG, or GIF) have no concept of layers - so that the base would be one layer, and the watermark another: the result is just one layer, onto which both were redrawn. This is somewhat similar to a physical painting: if you paint one image on a paper using watercolors, and then another over the same spot, their colors will mix and you won't be able to tell which parts belong to one or the other, as they'd become a single image.
This is similar with the computer image formats: there is only one "layer", which for every pixel encodes exactly one color that is there - only the current color exists, and the image doesn't keep track what was on that pixel before.
Now, the information is irreversibly lost from the result - in other words, it is not possible to recover the base knowing just the result (or the result and watermark) - BTW, that's exactly the point of watermarking.
I have borrowed the image sprites of StackOverflow for a demonstration; the actual images used are not unique, the technique would work just as well with any images. This was the watermark I used:
And this is the result image, after merging with the base:
Now, even though we have the exact watermark image used, there's no way to recover what was underneath that star in the original image. Through image processing operations, we could almost remove the star from the result, but there's not enough data to tell us what used to be underneath: - that information got erased in the merge at the beginning.
We could guess what used to be there, but then we're not doing recovery any more, we're interpreting the image and guessing what possibly could have been there - and that's pretty hard, even for a human; computers are really bad at that. This is the original image, before I watermarked it - I bet you were expecting something slightly different, no?
The watermark is almost certainly part of the image. (The only case in which it wouldn't be is something like PDF or SVG, where it could be a separate vector element.)
Watermarks are typically present on images for purposes of managing intellectual property; if one has licensed an image for a particular use, typically one will receive access to a version of the image without a watermark. Thus wanting to "remove watermarks" is also likely to be treated as highly suspicious.
Watermarks are part of the image, there isn't going to be a magic way to remove them and recover the missing pixels in any tool.
Take a look at the source! Most or the current watermarking is done in php as an automated script. In most cases you will see the base picture in source