watermarking in Tiff

i am tring add a watermark on my file. but i am getting error 'A Graphics object cannot be created from an image that has an indexed pixel format'

Here is my code . please give a solution for this

string text = DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss");

string fileName = @"C: \Users\ENGAPP73\Desktop\t4.tiff";

string watermarkText = "2914 View: " + text;

Stream stream = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read);

System.Drawing.Image image = System.Drawing.Image.FromStream(stream);

using (Graphics grp = Graphics.FromImage(image))

{

Brush brush = new SolidBrush(Color.Red);

Font font = new Font("Arial", 30.0f, FontStyle.Bold, GraphicsUnit.Pixel);

SizeF textSize = grp.MeasureString(watermarkText, font);

Point position = new Point((image.Width - ((int)textSize.Width + 10)), (image.Height - ((int)textSize.Height + 10)));

grp.DrawString(watermarkText, font, brush, position);

stream.Dispose();

File.Delete(fileName);

image.Save(fileName);

The System.Drawing.Graphics class doesn't support drawing to palletized or indexed images like the TIFF you are using. The most direct approach would be to convert the TIFF to an image format that is supported by GDI+.

On the other hand, if you do not want to convert the TIFF image, you can try using an imaging toolkit like LEADTOOLS (https://www.leadtools.com/). (Disclaimer: I am an employee of this toolkit’s vendor).

The LEADTOOLS toolkit supports multiple TIFF formats and a number of image processing features that you can use to create a watermark.

The code for doing this in LEADTOOLS would look like this:

using (RasterCodecs codecs = new RasterCodecs())
{
RasterImage img = codecs.Load(stream);
using (var g = new RasterImageGdiPlusGraphicsContainer(img))
using (var brush = new SolidBrush(Color.Red))
using (var font = new Font("Arial", 30.0f, FontStyle.Bold, GraphicsUnit.Pixel))
{
var rect = new RectangleF(0, 0, img.Width, img.Height);
g.Graphics.DrawString(text, font, brush, rect, StringFormat.GenericDefault);
}
}

1 Reply

Know the answer? Post it — somebody with the same question will find it here.

Hussam Barouqa7y ago
The System.Drawing.Graphics class doesn't support drawing to palletized or indexed images like the TIFF you are using. The most direct approach would be to convert the TIFF to an image format that is supported by GDI+.
On the other hand, if you do not want to convert the TIFF image, you can try using an imaging toolkit like LEADTOOLS (https://www.leadtools.com/). (Disclaimer: I am an employee of this toolkit’s vendor).
The LEADTOOLS toolkit supports multiple TIFF formats and a number of image processing features that you can use to create a watermark.
The code for doing this in LEADTOOLS would look like this:
using (RasterCodecs codecs = new RasterCodecs())
{
   RasterImage img = codecs.Load(stream);
   using (var g = new RasterImageGdiPlusGraphicsContainer(img))
   using (var brush = new SolidBrush(Color.Red))
   using (var font = new Font("Arial", 30.0f, FontStyle.Bold, GraphicsUnit.Pixel))
   {
      var rect = new RectangleF(0, 0, img.Width, img.Height);
      g.Graphics.DrawString(text, font, brush, rect, StringFormat.GenericDefault);
   }
}