Text on image - watermark - font size

Question

I have images, that are stored in sql server. One of the images is retrieved, into a memory stream, then returned as an Image object. I then have a method called addWatermark(string text, Image img) Graphics g = Graphics.FromImage(image); g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias; g.DrawString(text, new Font("Tahoma",fontSize), Brushes.White, new PointF(0, 0)); i want the text to take up around 70% of the width of the image... im trying to calculate the value fontSize the image thats passed in could be any size.... not always the same size. Basically, i need to calculate the max font size, then reduce it by 30% i guess. any ideas?

Bilal Amjad · Answer

The uploaded Image will have text watermark. [HttpPost] public ActionResult Index(HttpPostedFileBase postedFile) { if (postedFile != null ) { string watermarkText = "Watermark Text" ; //Get the file name. string fileName = Path.GetFileNameWithoutExtension(postedFile.FileName) + ".png" ; //Read the File into a Bitmap. using (Bitmap bmp = new Bitmap(postedFile.InputStream, false )) { using (Graphics grp = Graphics.FromImage(bmp)) { //Set the Color of the Watermark text. Brush brush = new SolidBrush(Color.Red); //Set the Font and its size. Font font = new System.Drawing.Font( "Arial" , 30, FontStyle.Bold, GraphicsUnit.Pixel); //Determine the size of the Watermark text. SizeF textSize = new SizeF(); textSize = grp.MeasureString(watermarkText, font); //Position the text and draw it on the image. Point position = new Point((bmp.Width - (( int )textSize.Width + 10)), (bmp.Height - (( int )textSize.Height + 10))); grp.DrawString(watermarkText, font, brush, position); using (MemoryStream memoryStream = new MemoryStream()) { //Save the Watermarked image to the MemoryStream. bmp.Save(memoryStream, ImageFormat.Png); memoryStream.Position = 0; return File(memoryStream.ToArray(), "image/png" , fileName); } } } } return View(); } }

Dipal Choksi · Answer

Is your watermark going to be a fixed text string? If yes, you could calculate the watermark width based on the specific string and scale it based on the image size you apply the watermark to. You might have already seen this one - an article on adding a watermark - http://www.codeproject.com/KB/GDI-plus/watermark.aspx