Question

How can I programatically determine the image format of an image file, including the specific encoding such as the TIFF group?

Answer 1

see my answer here:

Find image format using Bitmap object in C#

using System.Linq;

//...

//get image
var file_bytes = System.Convert.FromBase64String(@"iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg==");
var file_stream = new System.IO.MemoryStream(file_bytes);
var file_image = System.Drawing.Image.FromStream(file_stream);

//get image format
var file_image_format = typeof(System.Drawing.Imaging.ImageFormat).GetProperties(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Static).ToList().ConvertAll(property => property.GetValue(null, null)).Single(image_format => image_format.Equals(file_image.RawFormat));
System.Diagnostics.Debug.WriteLine(file_image_format, "file_image_format");

//get image codec
var file_image_format_codec = System.Drawing.Imaging.ImageCodecInfo.GetImageDecoders().ToList().Single(image_codec => image_codec.FormatID == file_image.RawFormat.Guid);
System.Diagnostics.Debug.WriteLine(file_image_format_codec.CodecName + ", mime: " + file_image_format_codec.MimeType + ", extension: " + file_image_format_codec.FilenameExtension, "image_codecs", "file_image_format_type");