/// <summary>
/// Asynchronously calculate difference between provided images
/// </summary>
/// <param name="errorTolerance">Maximum allowed pixel delta</param>
/// <param name="maxDifferences">Maximum differences to recognize</param>
/// <returns>Image with highlighted differences</returns>
public async Task <Image> CalculateAsync(double errorTolerance, int maxDifferences = int.MaxValue)
{
using var leftCopy = new Bitmap(_left);
using var rightCopy = new Bitmap(_right);
var leftBits = leftCopy.LockBits(
new Rectangle(0, 0, leftCopy.Width, leftCopy.Height),
ImageLockMode.ReadWrite,
PixelFormat.Format32bppArgb);
var rightBits = rightCopy.LockBits(
new Rectangle(0, 0, rightCopy.Width, rightCopy.Height),
ImageLockMode.ReadWrite,
PixelFormat.Format32bppArgb);
if (await PreprocessAsync(leftBits, rightBits) && _progressObserver != null)
{
await _progressObserver.ReportAsync(leftCopy, "leftPreprocess");
await _progressObserver.ReportAsync(rightCopy, "rightPreprocess");
}
var pixels = await _diffAlgorithm.GetDifferentPixelsAsync(errorTolerance, leftBits, rightBits, _progressObserver);
leftCopy.UnlockBits(leftBits);
rightCopy.UnlockBits(rightBits);
var result = new Bitmap(_left);
if (_diffHighlighter != null)
{
await _diffHighlighter.HighlightAsync(result, pixels, maxDifferences, _progressObserver);
}
return(result);
}
public async Task <IPixelBuffer> GetDifferentPixelsAsync(double errorTolerance, BitmapData left, BitmapData right, IDiffProgressObserver progress = null)
{
var result = GenerateDiffMap(errorTolerance, left, right);
if (progress == null)
{
return(result);
}
using var report = new ReportBuilder(left.Width, left.Height).AddPixels(result, Color.Red).Build();
await progress.ReportAsync(report, "diffMap");
return(result);
}
public async Task HighlightAsync(Image target, IPixelBuffer pixels, int limit, IDiffProgressObserver progress = null)
{
using var g = Graphics.FromImage(target);
await foreach (var cluster in _clusteringAlgorithm.GetClustersAsync(pixels, limit))
{
g.DrawRectangle(_pen, cluster);
if (progress == null)
{
continue;
}
using var report = new ReportBuilder(target).AddRectangle(cluster, _pen).Build();
await progress.ReportAsync(report, "rect");
}
}