I am saving PNG images and would like each individual image to have its own version number.
I was originally doing this in C# and saving every PNG file and adding on ?v=54165 which gives the file its own unique number while keeping it as a png, so for example the whole file would look like this:
imagename.png?v=67485
The problem is that in Windows you cannot save an image with a question mark in the filename as it is a reserved character. I would be grateful if someone could provide an alternative?
EDIT: I need the number to be after the file extension.
Sorry, it is not possible in Windows to add any information after extension in filename. It is better to save image as
'imagename__v67485.png' to avoid complexity in filename
Related
I am working on a system that saves temporary files in windows\temp. These files take on a .tmp file extension.
I am working on functionality that needs to read one of these files, identify whether it is an image or video file, and the filetype. Since the files are saved as .tmp, I can not use the file extension.
I've already written code that identifies whether the file is a valid image file, and it's filetype - This was actually quite easy, to my surprise!
My question is this: How can I identify whether an array of bytes is a valid video file, and if it is, how can I identify it's filetype?
As I understand, this is in general not an easy task as there are hundreds of formats. But I guess if you learn about binary signatures, or file signatures, you'll get a step forward with this question.
Here is an idea:
http://www.den4b.com/wiki/ReNamer:Binary_Signatures
And here more information:
http://en.wikipedia.org/wiki/List_of_file_signatures
Good luck :-)
I have a task to programamatically scan a folder for georeferenced images. There might be a lot of images, some quite large, and some not georeferenced. The spatial information can also be either embedded or in a world file.
How can I tell programmatically (C#/WPF/ESRI Runtime) if "C:\someFolder\file.x" is georeferenced?
Thanks
First check the file type to see if it's a format that supports built in georeferencing (GeoTiff, jp2, and MrSid). Other static image files would need some sort of companion file with the georeferencing information. So for each image file you'd want to look for a matching companion file.
If you add some info on what formats the images/world files are in it'll be easier to show you some sample code.
I have already seen solution for hiding text files or messages within Image or audio files..
but i want solution for hiding text file within another text files (.txt, .doc, .pdf).
can somebody help for this??
Steganography is based on slightly changing data to "hide" some other set of data within these changes. That's why an image with steganography is slightly different than the original. You can't notice if if you don't know it's there, but the fact is you saved the data as changes within color information of pixels.
.txt file is nothing else than a big hunk of characters. If you tried to somehow change the data to hide something in it, it would result in unreadable text. If you change the color of a pixel from 215 Red to 217 Red, you won't really notice. But changing A to F or Ł is quite noticable.
So no, I don't believe it can be done. At least not with .txt files.
While I agree with #stonehead that at the end of the day if you put something in the file someone can find it, but there are a few tricks out their that may prove to be viable options.
Since most users are not living in their command prompt the most straight forward approach is to misrepresent the file to the GUI. This is a pretty handy trick for this.
http://www.howtogeek.com/howto/windows-vista/stupid-geek-tricks-hide-data-in-a-secret-text-file-compartment/
If you are storing data in a pdf you should have very little problems. I would use PdfClown. Not to get too into it but you will want to read up about the structure of a pdf. With clown pdf you could store an asset inside with no connection to the presentation layer. Given the complexity of pdf files i will almost bet no one will be looking in, i would base64encode the chunk to have it blend in with images and other data it would be difficult for someone to find it by just opening up the file.
Be For Warned ClownPDF C# library is not for the faint of heart and it will help to have some java experience because a lot of their docs are for java.
Hope these options help.
There is a virus that my brother got in his computer and what that virus did was to rename almost all files in his computer. It changed the file extensions as well. so a file that might have been named picture.jpg was renamed to kjfks.doc for example.
so what I have done in order to solve this problem is:
remove all file extensions from files. (I use a recursive method to search for all files in a directory and as I go through the files I remove the extension)
now the files do not have an extension. the files now look like:
I think this file names are stored in a local database created by the virus and if I purchase the anti virus they will be renamed back to their original name.
since my brother created a backup I selected the files that had a creation date latter than when my brother performed the backup. so I have placed that files in a directory.
I am not interested in getting the right extension as long as I can see the content of the file. for example, I will scan each file and if it has text inside I know it will have a .txt extension. maybe it was a .html or .css extension I will not be able to know that I know.
I belive that all pdf files should have something in common. or doc files should also have something in common. How can I figure what the most common types (pdf, doc, docx, png, jpg, etc) files have in common)
Edit:
I know it will probably take less time to go over all this 200 files and test each one instead of creating this program. it is just that I am curios to see if it will be possible to get the file extension.
In unix, you can use file to determine the type of file. There is also a port for windows and you can obviously write a script (batch, powershell, etc.) or C# program to automate this.
First, congratulate your brother on doing a backup. Many people don't, and are absolutely wiped out by these problems.
You're going to have to do a lot of research, I'm afraid, but you're on the right track.
Open each file with a TextReader or a BinaryReader and examine the headers. Most of them are detectable.
For instance: Every PDF starts with "%PDF-" and then its version number. Just look at those first 5 characters. If it's "%PDF-", then put a PDF on the filename and move on.
Similarly: "ÿØÿà..JFIF" for JPEG's, "[InternetShortcut]" for URL shortcuts, "L...........À......Fƒ" for regular shortcuts (the "." is a zero/null, BTW)
ZIPs / Compressed directories start with {0x50}{0x4B]{0x03}{0x04}{0x14}, and you should be aware that Office 2007/2010 documents are really ZIPs with XML files inside of them.
You'll have to do some digging as you find each type, but you should be able to write something to establish most of the file types.
You'll have to write some recursion to work through directories, but you can eliminate any file with no extension.
BTW - A great tool to help pwith this is HxD: http://www.mh-nexus.de/ It's what I used to pull this answer together!
Good luck!
"most common types" each have it's own format and most of them have some magic bytes at the fixed position near beginning of the file. You can detect most of formats quite easily. Even HTML, XML, .CSS and similar text files can be detected by analyzing their beginning. But it will take some time to write an application that will guess the format. For some types (such as ODF format or JAR format, which are built on top of regular ZIPs) you will be also able to detect this format.
But ... Can it be that there exists such application on the market? I guess you can find something if you search, cause the task is not as tricky as it initially seems to be.
I am currently working on a project to hide data inside an mp3 file...What I did was, I replaced the last BYTE of every mp3 frame with the bytes from message file(the file to be hidden)... It works fine... I could hide the file in it and also successfully extract it... But some noise are present in the resulting mp3 file, due to addition of external data which is, definitely, not desired... Please help me in where to store the data in mp3 so as to reduce the noise...
PS: There is already a tool to use mp3 for hiding data -Mp3Stego. But it takes uncompressed wav file as input. But I need to have mp3 as input.
Such kind of tools do not replace whole byte. They are replace only last BIT. Try to replace only a BIT instead of BYTE. This will reduce the noise, but also reduce size of an information which you can put in file.