public void estimateBlackPoint(BlackPointEstimationMethod method, int argument)
{
if (!method.Equals(lastMethod) || argument != lastArgument)
{
int width = getWidth();
int height = getHeight();
int[] histogram = new int[LUMINANCE_BUCKETS];
if (method.Equals(BlackPointEstimationMethod.TWO_D_SAMPLING))
{
int minDimension = width < height ? width : height;
int startX = (width - minDimension) >> 1;
int startY = (height - minDimension) >> 1;
for (int n = 0; n < minDimension; n++)
{
int luminance = getLuminance(startX + n, startY + n);
histogram[luminance >> LUMINANCE_SHIFT]++;
}
}
else if (method.Equals(BlackPointEstimationMethod.ROW_SAMPLING))
{
if (argument < 0 || argument >= height)
{
throw new Exception("Row is not within the image: " + argument);
}
initLuminances();
luminances = getLuminanceRow(argument, luminances);
for (int x = 0; x < width; x++)
{
histogram[luminances[x] >> LUMINANCE_SHIFT]++;
}
}
else
{
throw new Exception("Unknown method: " + method);
}
blackPoint = BlackPointEstimator.estimate(histogram) << LUMINANCE_SHIFT;
lastMethod = method;
lastArgument = argument;
}
}
public BitArray getBlackRow(int y, BitArray row, int startX, int getWidth)
{
if (row == null || row.getSize() < getWidth)
{
row = new BitArray(getWidth);
}
else
{
row.clear();
}
// Reuse the same int array each time
initLuminances();
luminances = getLuminanceRow(y, luminances);
// If the current decoder calculated the blackPoint based on one row, assume we're trying to
// decode a 1D barcode, and apply some sharpening.
if (lastMethod.Equals(BlackPointEstimationMethod.ROW_SAMPLING))
{
int left = luminances[startX];
int center = luminances[startX + 1];
for (int x = 1; x < getWidth - 1; x++)
{
int right = luminances[startX + x + 1];
// Simple -1 4 -1 box filter with a weight of 2
int luminance = ((center << 2) - left - right) >> 1;
if (luminance < blackPoint)
{
row.set(x);
}
left = center;
center = right;
}
}
else
{
for (int x = 0; x < getWidth; x++)
{
if (luminances[startX + x] < blackPoint)
{
row.set(x);
}
}
}
return(row);
}
public void estimateBlackPoint(BlackPointEstimationMethod method, int argument){
if (!method.Equals(lastMethod) || argument != lastArgument) {
int width = getWidth();
int height = getHeight();
int[] histogram = new int[LUMINANCE_BUCKETS];
if (method.Equals(BlackPointEstimationMethod.TWO_D_SAMPLING)) {
int minDimension = width < height ? width : height;
int startX = (width - minDimension) >> 1;
int startY = (height - minDimension) >> 1;
for (int n = 0; n < minDimension; n++) {
int luminance = getLuminance(startX + n, startY + n);
histogram[luminance >> LUMINANCE_SHIFT]++;
}
} else if (method.Equals(BlackPointEstimationMethod.ROW_SAMPLING)) {
if (argument < 0 || argument >= height) {
throw new Exception("Row is not within the image: " + argument);
}
initLuminances();
luminances = getLuminanceRow(argument, luminances);
for (int x = 0; x < width; x++) {
histogram[luminances[x] >> LUMINANCE_SHIFT]++;
}
} else {
throw new Exception("Unknown method: " + method);
}
blackPoint = BlackPointEstimator.estimate(histogram) << LUMINANCE_SHIFT;
lastMethod = method;
lastArgument = argument;
}
}
