/// <summary>
/// Compares two images based on defined set up.
/// </summary>
/// <returns>An instance of <see cref="ComparisonResult"/> that results of comparison.</returns>
public ComparisonResult Compare()
{
if (_baselineImage == null)
{
throw new ArgumentNullException(nameof(_baselineImage), "Baseline image is required. Use CompareTo(...) method.");
}
if (_scaleToSameSize)
{
_actualImage = _resizer.Resize(_actualImage, _baselineImage.Width, _baselineImage.Height);
}
var comparisonAreaWidth = _actualImage.Width > _baselineImage.Width
? _actualImage.Width
: _baselineImage.Width;
var comparisonAreaHeight = _actualImage.Height > _baselineImage.Height
? _actualImage.Height
: _baselineImage.Height;
var comparisonResultImage = new Bitmap(comparisonAreaWidth, comparisonAreaHeight);
var pixelMismatchCount = 0;
var differenceBounds = new DifferenceBounds
{
Top = comparisonAreaHeight,
Left = comparisonAreaWidth,
Bottom = 0,
Right = 0
};
void updateBounds(int x, int y)
{
differenceBounds.Left = Math.Min(x, differenceBounds.Left);
differenceBounds.Right = Math.Max(x, differenceBounds.Right);
differenceBounds.Top = Math.Min(y, differenceBounds.Top);
differenceBounds.Bottom = Math.Max(y, differenceBounds.Bottom);
}
var startTime = DateTime.Now;
var skipTheRest = false;
for (var horizontalPosition = 0; horizontalPosition < comparisonAreaWidth; horizontalPosition++)
{
for (var verticalPosition = 0; verticalPosition < comparisonAreaHeight; verticalPosition++)
{
if (skipTheRest ||
!IsPixelInBounds(_actualImage, horizontalPosition, verticalPosition) ||
!IsPixelInBounds(_baselineImage, horizontalPosition, verticalPosition))
{
break;
}
var actualPixel = _actualImage.GetPixel(horizontalPosition, verticalPosition);
var expectedPixel = _baselineImage.GetPixel(horizontalPosition, verticalPosition);
var errorPixel = GetColorOfDifference(_settings.DifferenceType.Value)(actualPixel, expectedPixel);
var isPixelComparable = IsPixelComparable(expectedPixel, horizontalPosition, verticalPosition);
if (_ignoreColors)
{
if (IsPixelBrightnessSimilar(actualPixel, expectedPixel) || !isPixelComparable)
{
if (!_compareOnly && _settings.DifferenceType != DifferenceType.DiffOnly)
{
SetGrayScaledPixel(comparisonResultImage, expectedPixel, horizontalPosition, verticalPosition);
}
}
else
{
if (!_compareOnly)
{
comparisonResultImage.SetPixel(horizontalPosition, verticalPosition, errorPixel);
}
pixelMismatchCount++;
updateBounds(horizontalPosition, verticalPosition);
}
continue;
}
if (IsRGBSimilar(actualPixel, expectedPixel) || !isPixelComparable)
{
if (!_compareOnly && _settings.DifferenceType != DifferenceType.DiffOnly)
{
SetTransparentPixel(comparisonResultImage, actualPixel, horizontalPosition, verticalPosition);
}
}
else if (
_ignoreAntialiasing &&
(IsAntialiased(_actualImage, horizontalPosition, verticalPosition) ||
IsAntialiased(_baselineImage, horizontalPosition, verticalPosition))
)
{
if (IsPixelBrightnessSimilar(actualPixel, expectedPixel) || !isPixelComparable)
{
if (!_compareOnly && _settings.DifferenceType != DifferenceType.DiffOnly)
{
SetGrayScaledPixel(comparisonResultImage, expectedPixel, horizontalPosition, verticalPosition);
}
}
else
{
if (!_compareOnly)
{
comparisonResultImage.SetPixel(horizontalPosition, verticalPosition, errorPixel);
}
pixelMismatchCount++;
updateBounds(horizontalPosition, verticalPosition);
}
}
else
{
if (!_compareOnly)
{
comparisonResultImage.SetPixel(horizontalPosition, verticalPosition, errorPixel);
}
pixelMismatchCount++;
updateBounds(horizontalPosition, verticalPosition);
}
if (_compareOnly)
{
var currentMisMatchPercent = (double)pixelMismatchCount / (comparisonAreaHeight * comparisonAreaWidth) * 100;
if (currentMisMatchPercent > _returnEarlyThreshold)
{
skipTheRest = true;
}
}
}
}
var rawMisMatchPercentage = (float)pixelMismatchCount / (comparisonAreaHeight * comparisonAreaWidth) * 100;
return(new ComparisonResult
{
DiffBounds = differenceBounds,
Mismatch = rawMisMatchPercentage,
AnalysisTime = DateTime.Now - startTime,
ImageDifference = !_compareOnly
? ImageOperations.ConvertToBase64(comparisonResultImage)
: null,
IsSameDimensions =
_actualImage.Width == _baselineImage.Width &&
_actualImage.Height == _baselineImage.Height,
DimensionDifference = new DimensionDifference
{
Width = _actualImage.Width - _baselineImage.Width,
Height = _actualImage.Height - _baselineImage.Height
}
});
}