Inexpensive way of getting image size in .NET

sparkey196 · 20 Jan 2009 at 16:09

Hi,

Is there a way of getting the dimensions of a .jpg, .png, and .gif in .NET without having to read the entire image which consumes a shed load of memory. If a user uploads a 100000px image to my site, I would just like to discard it without exposing myself to a DoS attack. There must be some kind of libs for getting this from the image header info.

philjohn · 20 Jan 2009 at 20:44

I know that ImageMagick has an identify command that will output the type of image and dimensions - you can also install it as a component and use the API on Windows.

Inquisitor · 20 Jan 2009 at 21:28

Alternatively, you could always pull it from the image's raw binary

http://www.64lines.com/jpeg-width-height

philjohn · 20 Jan 2009 at 22:37

Inquisitor said:
Alternatively, you could always pull it from the image's raw binary

http://www.64lines.com/jpeg-width-height

Problem is, that only does jpeg, OP wants other formats too - rather than coding something like that up, just use a pre-existing library.

Inquisitor · 20 Jan 2009 at 23:45

philjohn said:
Problem is, that only does jpeg, OP wants other formats too - rather than coding something like that up, just use a pre-existing library.

Touché!

sparkey196 · 26 Jan 2009 at 12:09

philjohn said:
I know that ImageMagick has an identify command that will output the type of image and dimensions - you can also install it as a component and use the API on Windows.

Thanks, this worked really nicely. I made a 200MB image and identify returned the dimensions instantly

.

There is a .NET wrapper called MagickNet but the website contains viruses according to google?! I went to the site anyway and it seemed fine - no warnings from kaspersky AV.