private void UpdateImages()
{
// only perform if image was already loaded
if (!imageLoaded)
{
return;
}
// prepares quantizer
errorCache.Clear();
// tries to retrieve an image based on HSB quantization
Int32 parallelTaskCount = activeQuantizer.AllowParallel ? Convert.ToInt32(listParallel.Text) : 1;
TaskScheduler uiScheduler = TaskScheduler.FromCurrentSynchronizationContext();
Int32 colorCount = GetColorCount();
// disables all the controls and starts running
sourceImage = Image.FromFile(dialogOpenFile.FileName);
Text = Resources.Running;
SwitchControls(false);
DateTime before = DateTime.Now;
// quantization process
Task quantization = Task.Factory.StartNew(() =>
targetImage = ImageBuffer.QuantizeImage(sourceImage, activeQuantizer, activeDitherer, colorCount, parallelTaskCount),
TaskCreationOptions.LongRunning);
// finishes after running
quantization.ContinueWith(task =>
{
// detects operation duration
TimeSpan duration = DateTime.Now - before;
TimeSpan perPixel = new TimeSpan(duration.Ticks / (sourceImage.Width * sourceImage.Height));
// detects error and color count
Int32 originalColorCount = activeQuantizer.GetColorCount();
String nrmsdString = string.Empty;
// calculates NRMSD error, if requested
if (checkShowError.Checked)
{
Double nrmsd = ImageBuffer.CalculateImageNormalizedMeanError(sourceImage, targetImage, parallelTaskCount);
nrmsdString = string.Format(" (NRMSD = {0:0.#####})", nrmsd);
}
// spits some duration statistics (those actually slow the processing quite a bit, turn them off to make it quicker)
editSourceInfo.Text = string.Format("Original: {0} colors ({1} x {2})", originalColorCount, sourceImage.Width, sourceImage.Height);
editTargetInfo.Text = string.Format("Quantized: {0} colors{1}", colorCount, nrmsdString);
// new GIF and PNG sizes
Int32 newGifSize, newPngSize;
// retrieves a GIF image based on our HSB-quantized one
GetConvertedImage(targetImage, ImageFormat.Gif, out newGifSize);
// retrieves a PNG image based on our HSB-quantized one
GetConvertedImage(targetImage, ImageFormat.Png, out newPngSize);
// spits out the statistics
Text = string.Format("Simple palette quantizer (duration 0:{0:00}.{1:0000000}, per pixel 0.{2:0000000})", duration.Seconds, duration.Ticks, perPixel.Ticks);
editProjectedGifSize.Text = projectedGifSize.ToString();
editProjectedPngSize.Text = sourceFileInfo.Length.ToString();
editNewGifSize.Text = newGifSize.ToString();
editNewPngSize.Text = newPngSize.ToString();
pictureTarget.Image = targetImage;
// enables controls again
SwitchControls(true);
}, uiScheduler);
}
