extract JPEG from PDF

gistfile1.cs

private void ExtractJPEG(string pdf)
{
    var dir1 = Path.GetDirectoryName(pdf);
    var fn = Path.GetFileNameWithoutExtension(pdf);
    var dir2 = Path.Combine(dir1, fn);
    if (!Directory.Exists(dir2)) Directory.CreateDirectory(dir2);

    using (var doc = new PdfDocument(pdf))
    {
        int n = doc.PageCount;
        for (int i = 1; i <= n; i++)
        {
            var page = doc.GetPage(i);
            var rsrc = page.GetObject("/Resources");
            if (rsrc == null) continue;
            var xobj = rsrc.GetObject("/XObject");
            if (xobj == null) continue;

            foreach (var key in xobj.Keys)
            {
                var obj = xobj.GetObject(key);
                if (obj != null
                    && obj.GetText("/Subtype") == "/Image"
                    && obj.GetText("/Filter") == "/DCTDecode")
                {
                    File.WriteAllBytes(
                        Path.Combine(dir2, string.Format("{0:0000}.jpg", i)),
                        obj.GetStreamBytes());
                }
            }
        }
    }
}