Dimensions of JPEG in Memory ?

[Paul McKenzie]

I'm not using a library because I planned on just writing the block of memory to disk.

Unless you know what you're doing, you don't want to mess around with an image format such as JPEG with home-made code. Leave that to the authors of these libraries to handle those details -- they spent years on it.

I was going to use GDI+ but in order to create an Image from memory it has to be an IStream and that looks like a pain. Can I easily create a JPEG object from a memory block using those libraries you mentioned ?

I don't know what GDI+ does internally, but if it converts the JPEG to a DIB or some compatible bitmap structure, manipulates it, and then writes it back from the compatible format to JPEG, that is not the same as manipulating the JPEG directly in memory.

The IJG library is one of the industry standard libraries to manipulate JPEG files, so I would expect you can do anything with it in terms of memory blocks. Why not read the documentation and look at the sample files?

Regards,

Paul McKenzie