public static byte[] Read(byte[] bytes, int width, int height, uint tolerance, byte[] debugBytes = null)
{
TagImage tagImage = new TagImage()
{
Bytes = bytes,
Width = width,
Height = height,
ColorDifferenceTolerance = tolerance
};
#if DEBUG
if (debugBytes != null)
{
_debugImage = new TagImage()
{
Bytes = debugBytes,
Width = width,
Height = height
};
}
#endif
tagImage.BaseColor = tagImage.ReadColor(tagImage.CenterX, tagImage.CenterY);
int maxIterations = Mathf.Min(width, height) / 32;
if (maxIterations <= 0)
{
return(null);
}
if (!TryFindTagCenterCoordinatesAndRadius(tagImage, maxIterations))
{
return(null);
}
if (!TryFindStartingAngleAndSegmentSize(tagImage))
{
return(null);
}
if (!TryFindLayerSizeAndCount(tagImage))
{
return(null);
}
return(TryReadData(tagImage, out byte[] readBytes) ? readBytes : null);
}
private static bool TryFindLayerSizeAndCount(TagImage tagImage)
{
int layerSize = 0;
int layerCount = 0;
double angle = tagImage.CodeStartingAngle + tagImage.CodeSegmentSize / 2.0;
int startingIndex = tagImage.CodeRadius;
uint dataColor = 0;
int usedWidth = Math.Min(tagImage.CodeCenterX, tagImage.Width / 2);
// Find layer size
for (int i = startingIndex; i < tagImage.Width; i++)
{
CalculateCoords(tagImage, angle, i, out int x, out int y);
if (x < 0 || y < 0 || x > tagImage.Width || y > tagImage.Height)
{
continue;
}
uint color = tagImage.ReadColor(x, y);
uint diff = tagImage.ColorDiff(color);
if (diff < tagImage.ColorDifferenceTolerance)
{
continue;
}
dataColor = color;
layerSize = i - startingIndex - 1;
startingIndex = i;
break;
}
if (layerSize == 0 || layerSize == usedWidth)
{
return(false);
}
// Find size of the tag data block (layer size * layer count, starting from the first data layer)
int dataSize = -1;
for (int i = startingIndex; i < tagImage.Width; i++)
{
CalculateCoords(tagImage, angle, i, out int x, out int y);
if (x < 0 || y < 0 || x > tagImage.Width || y > tagImage.Height)
{
continue;
}
uint color = tagImage.ReadColor(x, y);
uint diff = TagImage.ColorDiff(color, dataColor);
if (diff < tagImage.ColorDifferenceTolerance)
{
continue;
}
dataSize = i - startingIndex - 1;
break;
}
if (dataSize < 0)
{
return(false);
}
layerCount = (int)Math.Round((double)dataSize / (double)layerSize);
tagImage.CodeLayerSize = layerSize;
tagImage.CodeLayerCount = layerCount;
return(true);
}
