Windows 2008 Task Scheduler Result Codes

I’ve been working on a PowerShell script that required to be automatically run every 5 minutes. As you probably guessed, using Windows Task Scheduler is the way to go.

Prior to assigning any scripts or programs to a scheduled task, I always run them manually first to ensure all issues are rectified.  We all know if there is an issue whilst running within Task Scheduler, Windows likes to help us by showing us some ambiguous error/success codes.

Luckily, MSDN provides a comprehensive list of these codes that can be found here: http://msdn.microsoft.com/en-us/library/aa383604

But there more common codes are listed below:

0 or 0x0: The operation completed successfully.
1 or 0x1: Incorrect function called or unknown function called.
2 or 0x2: File not found.
10 or 0xa: The environment is incorrect.
0x41300: Task is ready to run at its next scheduled time.
0x41301: Task is currently running.
0x41302: Task is disabled.
0x41303: Task has not yet run.
0x41304: There are no more runs scheduled for this task.
0x41306: Task is terminated.
0x8004131F: An instance of this task is already running.
0x800704DD: The service is not available (is 'Run only when an user is logged on' checked?)
0xC000013A: The application terminated as a result of a CTRL+C.
0xC06D007E: Unknown software exception.

Optimising Image Quality In System.Drawing

Sometimes optimising images to have an adequate image to file size ratio can be difficult when dynamically generating images using “System.Drawing”.

Over the years, I have worked on quite a few different projects around the use of “System.Drawing” and recently I found a flexible way of being able to have control over the image quality and file size.

Here’s a snippet of of code from my Generic Handler (.ashx) file:

public void ProcessRequest(HttpContext context)
{
    context.Response.ContentType = "image/jpeg";

    //Create a new Bitmap
    Bitmap oBitmap = new Bitmap(800, 800, PixelFormat.Format24bppRgb);

    //Load Background Graphic from Image
    Graphics oGraphics = Graphics.FromImage(oBitmap);

    #region Your Image Code
     
    //Insert your code here.

    #endregion

    #region Stage 1: Image Quality Options
    
    oGraphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
    oGraphics.SmoothingMode = SmoothingMode.HighQuality;
    oGraphics.PixelOffsetMode = PixelOffsetMode.HighQuality;
    oGraphics.CompositingQuality = CompositingQuality.HighQuality;
    
    #endregion

    //Clear graphic resources
    oGraphics.Dispose();

    #region Stage 2: Image Quality Options

    //Output image
    ImageCodecInfo[] Info = System.Drawing.Imaging.ImageCodecInfo.GetImageEncoders();
    EncoderParameters Params = new System.Drawing.Imaging.EncoderParameters(1);
    Params.Param[0] = new EncoderParameter(Encoder.Quality, 100L); //Set image quality
    context.Response.ContentType = Info[1].MimeType;
    oBitmap.Save(context.Response.OutputStream, Info[1], Params);

    #endregion
}

System.Drawing.Graphics Optimisations

In all my “System.Drawing” development projects, I’ve always set the graphic object quality options (lines 19-22) and found that it never really worked for me. The reason for this is because I always placed these settings after creating my System.Drawing.Graphics object prior to my custom code. So the image was getting optimised before any of my functionality had taken place. Rubbish!

The key is to set all your System.Drawing.Graphics object settings just before you dispose of it. Makes sense doesn’t it? Don’t know how I made such a noob mistake.

By default, .NET uses the web safe options when converting Bitmap to an image and setting those four properties will have a big affect on how your image looks.

Compression Level

This is the good bit!

.NET gives you the ability to carry out further tweaks on how your image will be rendered by allowing us to set the compression level. The compression level can be tweaked by modifying the value passed to the “EncoderParameter” constructor (line: 34).

For another example of how this can be used, take a look at the following MSDN article: http://msdn.microsoft.com/en-us/library/bb882583.aspx