I am trying to use steganography and exif to-gather can it be done ?? as in hide data in a file without destroying the exif image.
thanks
andy
As long as you only alter the pixel data and not any header-related data, then sure, why not?
Related
For some reason, JPG images in my company are stored with the first two bytes changed (very crude encryption?).
I need to open them in node.js to resize and watermark them. I got as far as reading the image file into a ReadStream but that appears to be the wrong approach.
Any help would be greatly appreciated.
I have a client that wants to be able to find their proprietary images other places on the internet if someone steals them.
Is there a way to add meta information that we can track for this purpose inside a jpg file?
My answer was getting too long for comment so posting it as answer.
you can add an entry in EXIF IFD(metadata in binary) of jpeg image. It is not visible in image as it is. There are many EXIF editor/reader tools which will allow you to edit/read it. for example you can add a particular string in makernote of jpeg.
As I said, there are tools available in market, this also means that people can edit also reset the complete EXIF metadata which will erase your data too....
To get around this you can add your copyrighted IFD entry which only you can understand. For this you have to edit some EXIF tool and tweak according to your need.
But while adding your entry in JPEG metadata please take care that you adhere to EXIF/TIFF specifications so that image is not corrupted and readable in all platforms.
Here are some links to help you understand EXIF/TIFF -
http://gvsoft.homedns.org/exif/exif-explanation.html
and
http://www.exif.org/Exif2-2.PDF
I'm working in vc++ 08. I need to read EXIF data of particular JPG file and modify it. In that mostly I need to read Latitude and Longitude data of JPG file and modify it. I searched for library that can give me access to EXIF data of JPG file but after all efforts I ended up here. I don't think there is any header file that can give me access of EXIF data of JPG file in vc++. Please help me out. Any examples will be appreciated. Or referce to any library for read and modify EXIF data of JPG file also appreciated.
Thanks in advance...
Try the Adobe XMP toolkit
It can work with EXIF GPS data - not just XMP and is native C++
Finally got it.
Use exiv2 library. It gives all access to exif data of image file. You can read and modify exif data very easily using this.
And more importantly it is free and open source.
Detailed usage : http://linux.die.net/man/1/exiv2
I want to develop a news App such as Engadge etc. The news had loaded from the server, and now I'll save the news included body text and pictures into database(Core Data). Can UIWebView read the datas from Core Data directly, and shows in UIWebview?
Thanks.
Yes and no. You can store the HTML content in the database (CoreData), to show an article you use: loadHTMLString:baseURL: of UIWebView to show the textual content. The images however is probably best stored outside the database as file because you will have to point the image references in your HTML to an actual file.
You could store the images as BLOBs but then you need to pull those blobs and write as files later for UIWebView to be able to pick them up.
I think the easiest way is to store images as files and but place references to them inside CoreData. That way you can also delete them accordingly later on.
If by directly, you mean without any glue code, then no, not on iOS as of present.
You could however use Core data to store text and image objects as desired. It might not be the best idea to use a UIWebView, but to answer your question, it's definitely possible, and in fact quite easy to do so.
I'm creating an excel-sheets that reads the tags from the MP3-files situated in a folder. Yet the time apparently is or calculated from data inside the MetaProperties of a file or is inside those data. When I use the Property MetaProperties VBA always provokes an error, even in using a copy of the example in adapting the appropiate data. Thanx in advance for your solution.
Does this help?
http://technet.microsoft.com/en-us/library/ee176591.aspx
You didn't say what metadata you want, but this method offers a lot of information.
MP3's do not use MetaProperties at all. They actually use the last 256 bytes of the file to store album, track, etc information (the ID3 tag).
See here http://id3.org/id3v2.4.0-structure for more information.