How to validate image file format in C#

Question

Hello Everyone, Does anyone know the script to validate what the file format is for a given image. Currently i am populating an image object, looking at it's height, width, and resolution. I don't see any specific properties off of this object that explains the file format.

I would like to check for jpg, AI, PSD, High Jes Jpg, Bitmap, and Tiff.

here is my current script:

        protected bool IsValidImage(HttpPostedFileBase file, string fileName) {

        //verify that the image is no more than 648 wide and 648 pixels tall
        Image imgPhoto = Image.FromStream(file.InputStream);
        if (imgPhoto.Width > 648)
            return false;
        if (imgPhoto.Height > 648)
            return false;
        if (imgPhoto.HorizontalResolution != 72 || imgPhoto.VerticalResolution != 72)
            return false;
        return true;

    }

Thanks in advance

Answer 1

Use Image.RawFormat. The result is an instance of the ImageFormat class which can be compared against the static properties of ImageFormat.

See http://msdn.microsoft.com/en-us/library/system.drawing.imaging.imageformat_members.aspx for more details.

Answer 2

You can visit Wotsit to find out the magic bytes used as a marker in the beginning of the file. Click on the 'Graphics File' to see the list of file formats.

Hope this helps, Best regards, Tom.

Answer 3

What about:

bool isJpeg = imgPhoto.RawFormat.Equals(Imaging.ImageFormat.Jpeg);