Watermark image doesn't work, get Blank image

Question

I am trying to apply a watermark text over an image in ASP.NET. I want to use Image stream instead of using / writing to local files.

Here's the code:

 using (MemoryStream ms_small = new MemoryStream())
  {

       System.Drawing.Image image_small = System.Drawing.Image.FromStream(filestream); 
       width = image_small.Width;
       height = image_small.Height;


       string Copyright = "Hi I am copyright watermark";

       Graphics grPhoto = Graphics.FromImage(image_small);

       int phWidth = image_small.Width;
       int phHeight = image_small.Height;

        grPhoto.SmoothingMode = SmoothingMode.AntiAlias;

       int[] sizes = new int[] { 16, 14, 12, 10, 8, 6, 4 };
       Font crFont = null;
       SizeF crSize = new SizeF();


       for (int i = 0; i < 7; i++)
       {
         crFont = new Font("arial", sizes[i], FontStyle.Bold);
         crSize = grPhoto.MeasureString(Copyright, crFont);
         if ((ushort)crSize.Width < (ushort)phWidth)
            break;
       }

       int yPixlesFromBottom = (int)(phHeight * .05);

       float yPosFromBottom = ((phHeight - yPixlesFromBottom) - (crSize.Height / 2));

       float xCenterOfImg = (phWidth / 2);


       StringFormat StrFormat = new StringFormat();
       StrFormat.Alignment = StringAlignment.Center;


       SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(153, 0, 0, 0));


        grPhoto.DrawString(Copyright,             
               crFont,                                  
               semiTransBrush2,                         
               new PointF(xCenterOfImg + 1, yPosFromBottom + 1),
                            StrFormat);

            SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(153, 255, 255, 255));
            grPhoto.DrawString(Copyright,            
                 crFont,                           
                 semiTransBrush,                          
                 new PointF(xCenterOfImg, yPosFromBottom), 
                 StrFormat);                      

                   Bitmap outputBitMap = new Bitmap(image_small.Width, image_small.Height, grPhoto);
                   image_small = (Image)outputBitMap;
                   ImageBuilder.Current.Build(image_small, ms_small, rs_small_jpg);

               }

The watermark code is from here.

Again, what I want to achieve is a watermark text on top of the image and without writing the image locally or using temporary local image file to apply the watermark. I am getting a blank image instead of the image with the watermark.

Answer 1

Your problem was in used graphics for image in end of method. Instead this, you must use original image, beacause all graphics were drawing in it.

Replace this string:

Bitmap outputBitMap = new Bitmap(image_small.Width, image_small.Height, grPhoto);

With this:

Bitmap outputBitMap = new Bitmap(imageSmall);

Good luck!

Answer 2

Your question was not clear, if you need to show generated image to page in asp.net HttpHandler is thing that you want. This post is sample of that Hope this helps.