How do i restrict file upload size in pixels

this is what i have at the moment

File.MaxSize = 1024*1024

With what component ??

However, You can't actually restrict the upload, until it's been uploaded then you can reject it.

Chris is right that something like this can't be done, as you need the entire file to open the image and find its pixel dimensions. He's even more right in that we need to know how you're doing this to give you any advice.

But, you could also come up with a max file size, and if you're streaming bytes in, you could count them and simply disconnect when the threshold is exceeded.