Question

I have created a handler for writing text on Image which call a function written below

private bool HavException { get; set; }
private string ExceptionMessage { get; set; }
public Bitmap SourceImage { get; set; }
public Bitmap DestinationImage { get; set; }
public ImageMethods()
{
    HavException = false;
    ExceptionMessage = string.Empty;
}
public Image AddWatermarkText(Image img, string textOnImage)
{
    try
    {
        textOnImage = ConfigurationManager.AppSettings["textOnImage"];
        var opacity = Int32.Parse(ConfigurationManager.AppSettings["opicity"]);
        var red = Int32.Parse(ConfigurationManager.AppSettings["red"]);
        var green = Int32.Parse(ConfigurationManager.AppSettings["green"]);
        var blue = Int32.Parse(ConfigurationManager.AppSettings["blue"]);
        var fontSize = Int32.Parse(ConfigurationManager.AppSettings["fontSize"]);
        var fontName = ConfigurationManager.AppSettings["fontName"];

        var lobFromImage = Graphics.FromImage(img);
        var lobFont = new Font(fontName, fontSize, FontStyle.Bold);
        var lintTextHw = lobFromImage.MeasureString(textOnImage, lobFont);
        var lintTextOnImageWidth = (int)lintTextHw.Width;
        var lintTextOnImageHeight = (int)lintTextHw.Height;
        var lobSolidBrush = new SolidBrush(Color.FromArgb(opacity, Color.FromArgb(red, green, blue)));
        // lobFromImage.Clear(Color.White);
        lobFromImage.DrawImage(img, img.Height, img.Width);

        var posLeft = (img.Width - lintTextOnImageWidth) / 2;
        posLeft = posLeft > 0 ? posLeft : 5;
        var lobPoint = new Point(posLeft, (img.Height / 2) - (lintTextOnImageHeight / 2));
        //  var lobPoint = new Point(RandomNumber(0, img.Width - lintTextOnImageWidth), RandomNumber(0, img.Height - lintTextOnImageHeight));
        lobFromImage.DrawString(textOnImage, lobFont, lobSolidBrush, lobPoint);

        lobFromImage.Save();
        lobFromImage.Dispose();
        lobSolidBrush.Dispose();
        lobFont.Dispose();
    }
    catch (Exception ex)
    {
        HavException = true;
        ExceptionMessage = ex.Message;
    }
    return img;
}

Every thing is working fine but the size of image is getting increased by 2 to three times.
Is there any way that the size does not increase too much. I have jpg as original image.

Thanks

Answer 1

Following call does not make sense and may be the culprit for inflating your image size:

lobFromImage.DrawImage(img, img.Height, img.Width);

This would draw the original image at (height, width) location – for example, if you have 200 x 100 image then above call would draw the image at (100, 200) location and possibly stretching your canvas to 300 x 300 size.

For adding the watermark, all you need to do is to draw the text – so my guess is by removing above line may do the trick.

Also lobFromImage.Save(); looks suspicious – it saves the graphic’s object state on stack and doesn’t have anything to do with saving the image on the disk.