/// <summary>
/// Applies simple sharpening to the row data to improve performance of the 1D Readers.
/// </summary>
/// <param name="y"></param>
/// <param name="row"></param>
/// <returns></returns>
public override BitArray getBlackRow(int y, BitArray row)
{
LuminanceSource source = LuminanceSource;
int width = source.Width;
if (row == null || row.Size < width)
{
row = new BitArray(width);
}
else
{
row.clear();
}
initArrays(width);
byte[] localLuminances = source.getRow(y, luminances);
int[] localBuckets = buckets;
for (int x = 0; x < width; x++)
{
localBuckets[(localLuminances[x] & 0xff) >> LUMINANCE_SHIFT]++;
}
int blackPoint;
if (!estimateBlackPoint(localBuckets, out blackPoint))
{
return(null);
}
if (width < 3)
{
// Special case for very small images
for (int x = 0; x < width; x++)
{
if ((localLuminances[x] & 0xff) < blackPoint)
{
row[x] = true;
}
}
}
else
{
int left = localLuminances[0] & 0xff;
int center = localLuminances[1] & 0xff;
for (int x = 1; x < width - 1; x++)
{
int right = localLuminances[x + 1] & 0xff;
// A simple -1 4 -1 box filter with a weight of 2.
// ((center << 2) - left - right) >> 1
if (((center * 4) - left - right) / 2 < blackPoint)
{
row[x] = true;
}
left = center;
center = right;
}
}
return(row);
}
/// <summary>
/// Fetches one row of luminance data from the underlying platform's bitmap. Values range from
/// 0 (black) to 255 (white). Because Java does not have an unsigned byte type, callers will have
/// to bitwise and with 0xff for each value. It is preferable for implementations of this method
/// to only fetch this row rather than the whole image, since no 2D Readers may be installed and
/// getMatrix() may never be called.
/// </summary>
/// <param name="y">The row to fetch, 0 <= y < Height.</param>
/// <param name="row">An optional preallocated array. If null or too small, it will be ignored.
/// Always use the returned object, and ignore the .length of the array.</param>
/// <returns>
/// An array containing the luminance data.
/// </returns>
override public byte[] getRow(int y, byte[] row)
{
row = @delegate.getRow(y, row);
int width = Width;
for (int i = 0; i < width; i++)
{
row[i] = (byte)(255 - (row[i] & 0xFF));
}
return(row);
}
public void testCrop()
{
Assert.IsTrue(SOURCE.CropSupported);
LuminanceSource cropped = SOURCE.crop(1, 1, 1, 1);
Assert.AreEqual(1, cropped.Height);
Assert.AreEqual(1, cropped.Width);
// java and .Net differs, not sure, why
//var expectedInJava = new byte[] {0x7F};
var expected = new byte[] { 0x95 };
Assert.AreEqual(expected, cropped.getRow(0, null));
}
// Applies simple sharpening to the row data to improve performance of the 1D Readers.
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in .NET:
//ORIGINAL LINE: public BitArray getBlackRow(int y, BitArray row) throws com.google.zxing.NotFoundException
public override BitArray getBlackRow(int y, BitArray row)
{
LuminanceSource source = LuminanceSource;
int width = source.Width;
if (row == null || row.Size < width)
{
row = new BitArray(width);
}
else
{
//row.SetAll(false);
row.clear();
}
initArrays(width);
sbyte[] localLuminances = source.getRow(y, luminances);
int[] localBuckets = buckets;
for (int x = 0; x < width; x++)
{
int pixel = localLuminances[x] & 0xff;
localBuckets[pixel >> LUMINANCE_SHIFT]++;
}
int blackPoint = estimateBlackPoint(localBuckets);
int left = localLuminances[0] & 0xff;
int center = localLuminances[1] & 0xff;
for (int x = 1; x < width - 1; x++)
{
int right = localLuminances[x + 1] & 0xff;
// A simple -1 4 -1 box filter with a weight of 2.
int luminance = ((center << 2) - left - right) >> 1;
if (luminance < blackPoint)
{
//row.Set(x, true);
row.set(x);
}
left = center;
center = right;
}
return(row);
}
