/**
* Run the Color Contrast calculation on the image.
*/
internal IColorContrastResult RunColorContrastCalculationV1()
{
ColorContrastResult result = null;
ColorContrastRunner runner = new ColorContrastRunner(_colorContrastConfig);
Color previousColor = null;
foreach (var pixel in GetBinaryRowSearchIterator())
{
if (IsNewRow(pixel))
{
runner.OnRowBegin();
}
runner.OnPixel(pixel.Color, previousColor);
previousColor = pixel.Color;
if (IsEndOfRow(pixel))
{
var newResult = runner.OnRowEnd();
if (result == null)
{
result = newResult;
}
// Save newResult if it's higher confidence than the current result.
// newResult.Confidence is guaranteed to be either High, Mid, or Low
if (newResult.Confidence == Confidence.High)
{
result = newResult;
break;
}
else if (newResult.Confidence == Confidence.Mid)
{
// The analyzer claims that this condition is always false, but testing
// proves that we definitely execute the code inside the if block.
#pragma warning disable CA1508 // Avoid dead conditional code
if (result.Confidence != Confidence.Mid)
#pragma warning restore CA1508 // Avoid dead conditional code
{
result = newResult;
}
}
}
}
return(result);
}
/**
* Run the Color Contrast calculation on the image.
*/
public ColorContrastResult RunColorContrastCalculation()
{
ColorContrastResult result = null;
ColorContrastRunner runner = new ColorContrastRunner(_colorContrastConfig);
Color previousColor = null;
foreach (var pixel in GetBinaryRowSearchIterator())
{
if (IsNewRow(pixel))
{
runner.OnRowBegin();
}
runner.OnPixel(pixel.Color, previousColor);
previousColor = pixel.Color;
if (IsEndOfRow(pixel))
{
var newResult = runner.OnRowEnd();
if (result == null)
{
result = newResult;
}
if (newResult.ConfidenceValue() == ColorContrastResult.Confidence.High)
{
result = newResult;
break;
}
else if (newResult.ConfidenceValue() == ColorContrastResult.Confidence.Mid &&
result.ConfidenceValue() == ColorContrastResult.Confidence.Low)
{
result = newResult;
}
}
}
return(result);
}
// Returns true when entries have lead to a confident conclusion about Text and Background color.
internal ColorContrastResult OnRowEnd()
{
ColorContrastResult result = new ColorContrastResult();
CountMap <ColorPair> pairsWithSimilarTextColor = new CountMap <ColorPair>();
foreach (var exactPairOuter in countExactPairs)
{
foreach (var exactPairInner in countExactPairs)
{
if (exactPairOuter.Key.backgroundColor.Equals(exactPairInner.Key.backgroundColor))
{
if (exactPairOuter.Key.foregroundColor.IsSimilarColor(exactPairInner.Key.foregroundColor))
{
pairsWithSimilarTextColor.Increment(exactPairOuter.Key, exactPairInner.Value);
}
}
}
}
var sortedByValueAndContrast = pairsWithSimilarTextColor.OrderByDescending(x => x.Value)
.ThenByDescending(x => x.Key.ColorContrast());
if (!sortedByValueAndContrast.Any())
{
return(result);
}
var resultPairs = new HashSet <ColorPair>();
var firstEntryCount = sortedByValueAndContrast.First().Value;
if (firstEntryCount < ColorContrastConfig.MinNumberColorTransitions)
{
return(result);
}
var firstEntryCountAdjusted = firstEntryCount / ColorContrastConfig.TransitionCountDominanceFactor;
foreach (var entry in sortedByValueAndContrast)
{
// Only Collect Pairs that have a reasonable occurence count.
if (entry.Value < firstEntryCountAdjusted)
{
break;
}
resultPairs.Add(entry.Key);
}
foreach (var colorPair in resultPairs)
{
result.Add(colorPair);
}
countExactColors.Clear();
openTransitions.Clear();
return(result);
}