Get Image dimensions in c# asp.net core (framework 4.6.1)

Question

Any idea on how to get an image dimensions in asp.net core, knowing that System.Drawing.Image doesn't work on this version. This is how I am actually reading the image:

byte[] data = File.ReadAllBytes("path_to_image");
return data;

ie: Can I find the Height and Width of an image in its byte[] representaion?

Any help in how to rotate the image is also welcome.

Answer 1

You want bytes 11-12 for Horizontal resolution, and 13-14 for Vertical resolution. Assuming you're talking about a JPEG image. And byte 10 gives you the unit type (dots per inch or dots per cm)

https://www.w3.org/Graphics/JPEG/jfif3.pdf