Reading a JPG image ...

... that is *not* in a JPG file.

Say I have a JPG picture data in a bank, but I dont have the .jpg file (data received by network stream, generated ...).

How can I read that data to view the picture ? The only solution I can think of right now is writing that data as a file then reading the file with loadimage or some other function.
However, as the tool im working on is supposed to read lots of images, think the writefile/loadimage method might not be the best thing.

I did a quick search for jpeg reading dlls but cound only find dll asking for a file name and not directly data.

Any idea ?

Maybe you can use the FreeImage.dll ? I've never used it, but here is a topic with .decls for it.
http://www.blitzbasic.com/Community/posts.php?topic=48558
There is a command that is called FIFromBank, which sounds promising..

if it is sent via network stream then why dont you use readpixel fast and then send that value? You can use writepixelfast to a buffer after you recieve it.

Warner > I tought of that but the library it works with a picture file.

Nate the great > Im not trying to make my life harder you know, if I could get the data in a more readable form, I would. : )

@Nate - because the pixels aren't simply stored pixel by pixel row by row in a jpeg, it is stored in the compressed jpeg format, which you'd need to either do as he says above, write to a file then load in, or learn the file format for jpeg and uncompress it himself in memory.

I would use DevIL. Dunno if anyone wrapped it for B3D already or not.

http://openil.sourceforge.net/features.php

Okay Sacha, just to check: you have the complete contents of the JPEG, just saved in a bank, right? Create a file, and dump the bank contents one byte at a time with something like this:

JPEG = WriteFile("image.jpg")


For i = 1 To BankSize(JPEGBank)
    WriteByte JPEG,PeekByte(JPEGBank,i - 1)
Next


CloseFile JPEG


Global Image = LoadImage("image.jpg")

That's just off the top of my head, you'll probably need to fiddle with it for it to work. Cheers!

See FiLoadFromBank.bb here.

Yes adam this works and is what Im currently using, however this is the 'bad' solution (write a file then reading it to get data we already have.

markcw > Thanks, thats seems to be exactly what I need, ill be trying that. : )