How to get the image dimension from the file name

Question

I have a file called FPN = "c:\ggs\ggs Access\images\members\1.jpg "

I'm trying to get the dimension of image 1.jpg, and I'd like to check whether image dimension is valid or not before loading, and if either width or height of the image is less than or equal to zero, pop up a message like "image not in correct format"

Can anyone help me please?

Answer 1

System.Drawing.Image img = System.Drawing.Image.FromFile(@"c:\ggs\ggs Access\images\members\1.jpg");
MessageBox.Show("Width: " + img.Width + ", Height: " + img.Height);

Answer 2

Wpf class System.Windows.Media.Imaging.BitmapDecoder doesn't read whole file, just metadata.

using(var imageStream = File.OpenRead("file"))
{
    var decoder = BitmapDecoder.Create(imageStream, BitmapCreateOptions.IgnoreColorProfile,
        BitmapCacheOption.Default);
    var height = decoder.Frames[0].PixelHeight;
    var width = decoder.Frames[0].PixelWidth;
}

Update 2019-07-07

If I remember correctly, few months later I found out that dealing with exif'ed images is a little bit more complicated. For some reasons iphones save rotated image instead of normal and they set "rotate this image before displaying" exif flag.
Also turned out that gif is pretty complicated format. It is possible that no frame has full gif size, you have to aggregate it from offsets and frames sizes.

So I used ImageProcessor instead, which dealed with all the problems for me. Never checked if it reads the whole file tho, because some browsers has no exif support and I had to save rotated version anyway.

using (var imageFactory = new ImageFactory())
{
    imageFactory
        .Load(stream)
        .AutoRotate(); //takes care of ex-if
    var height = imageFactory.Image.Height,
    var width = imageFactory.Image.Width
}