Image File Builder

• Download source code - 15.6 KB

Introduction

If you need to build a small, simple image file quickly, this utility makes it quite easy. The image file can be transparent, semitransparent, or opaque (any color), and as small as 1 pixel by 1 pixel. The image file can be saved as a GIF, JPEG, PNG, TIF, etc.

Background

Every now and then, for a web project or WinForms project, one needs to create an image file, perhaps a 1x16_transparent.png or a 32x16_red.gif or a 100x1_blue.jpeg. There are countless ways to create these. ImageFileBuilder, perhaps a pompous sounding name, just made my life a little easier.

Using the code

If you have Visual Studio 2005, then you should be able to use the project source code "out of the box" -- simply build and run. The code itself is not rocket science. It is reasonably documented. A side benefit of the code for Bitmap newbies is, it shows you simple examples of how to create a Bitmap, how to color it, and how to use the ImageFormat enum to save the file in a format that matches the requested file extension.

Code for creating a Bitmap with a given color

public Bitmap CreateBitmap(int width, int height, Color clr)
{
  try
  {
      Bitmap bmp = new Bitmap(width, height);

      for (int y = 0; y < bmp.Height; y++)
      {
          for (int x = 0; x < bmp.Width; x++)
          {
              bmp.SetPixel(x, y, clr);
          }
      }

      return bmp;
  }
  catch (Exception ex)
  {
      this.DoUpdateErrorMsg(ex.ToString());
      Debug.WriteLine(ex.ToString());
      return null;
  }
}

Code for saving a Bitmap with different file types

public bool SaveBitmap(Bitmap bmp, string sOutputFilename)
{
  bool bRet = false;
  try
  {
      FileInfo fiOutputFile = new FileInfo(sOutputFilename);

      //determine the image format from the file name
      ImageFormat imgFmtWant = ImageFormat.Png;
      switch (fiOutputFile.Extension.ToUpper())
      {
          case ".BMP" : imgFmtWant = ImageFormat.Bmp; break;
          case ".EMF" : imgFmtWant = ImageFormat.Emf; break;
          case ".EXF" :
          case ".EXIF": imgFmtWant = ImageFormat.Exif; break;
          case ".GIF" : imgFmtWant = ImageFormat.Gif; break;
          case ".ICO" : imgFmtWant = ImageFormat.Icon; break;
          case ".JPG" :
          case ".JPEG": imgFmtWant = ImageFormat.Jpeg; break;
          case ".PNG" : imgFmtWant = ImageFormat.Png; break;
          case ".TIF" :
          case ".TIFF": imgFmtWant = ImageFormat.Tiff; break;
          case ".WMF" : imgFmtWant = ImageFormat.Wmf; break;
          default: // none of the above, so add PNG to the name
              sOutputFilename += ".png";
              this.DoUpdateErrorMsg("WARNING: Output file " + 
                                    "name modified; Extension '.png' added.");
              break;
      }

      bmp.Save(sOutputFilename, imgFmtWant);
      bRet = true;
  }
  catch (Exception ex)
  {
      this.msErrorMsg += this.msEOL + ex.ToString();
      bRet = false;
  }
  return bRet;
}