/**
* Run the Color Contrast calculation on the image.
*/
public ColorContrastResult RunColorContrastCalculation()
{
var contrastResult = new ColorContrastResult();
ColorContrastResult oldContrastResult = null;
var colorContrastTransitions = new List <ColorContrastTransition>();
Pixel lastPixel = new Pixel(Color.WHITE, 0, 0);
foreach (var pixel in GetBinaryRowSearchIterator())
{
if (!lastPixel.Row.Equals(pixel.Row))
{
if (contrastResult.ConfidenceValue().Equals(Confidence.High))
{
return(contrastResult);
}
if (oldContrastResult == null)
{
oldContrastResult = contrastResult;
}
if (contrastResult.ConfidenceValue() > oldContrastResult.ConfidenceValue())
{
oldContrastResult = contrastResult;
}
}
colorContrastTransitions.Add(new ColorContrastTransition(pixel.Color));
foreach (var transition in colorContrastTransitions)
{
transition.AddColor(pixel.Color);
if (transition.IsPotentialForegroundBackgroundPair())
{
contrastResult.OnColorPair(transition.ToColorPair());
}
}
colorContrastTransitions.RemoveAll(transition => transition.IsStartingAndEndingColorSame());
lastPixel = pixel;
}
return(oldContrastResult);
}
/**
* Run the Color Contrast calculation on the image.
*/
public ColorContrastResult RunColorContrastCalculation()
{
ColorContrastResult result = null;
ColorContrastRunner runner = new ColorContrastRunner();
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.Count() <= 0)
{
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);
}
