Change the resolution of a jpeg image using C#

Question

I need to modify the vertical and horizontal resolutions without changing the image dimensions.

Answer 1

Check out the Bitmap.SetResolution Method.

Answer 2

If all you have is GDI, have a look at this link.

You can save the Bitmap to a JPEG file using this snippet:

bmp.Save("picture.jpg", System.Drawing.Imaging.ImageFormat.Jpeg);

Answer 3

The resolution is contained in EXIF tags within the JPEG file.

Here's one article that gives source code for doing similar things in C#:

http://www.codeproject.com/KB/graphics/EXIF_tag_Editor.aspx