@Test
public void testRealloc() {
BitMatrix bm = new BitMatrix(4, 4);
Assert.assertFalse(bm.resize(16, 1));
Assert.assertTrue(bm.getWidth() == 16);
Assert.assertTrue(bm.getHeight() == 1);
Assert.assertTrue(bm.resize(8, 3));
Assert.assertTrue(bm.getWidth() == 8);
Assert.assertTrue(bm.getHeight() == 3);
}
@Test
public void testNotEmpty() {
BitMatrix bm = new BitMatrix(4, 3);
Assert.assertFalse(bm.isEmpty());
Assert.assertTrue(bm.getWidth() == 4);
Assert.assertTrue(bm.getHeight() == 3);
Assert.assertTrue(bm.getSize() == 12);
}
@Test
public void testEmpty() {
BitMatrix bm = new BitMatrix();
Assert.assertTrue(bm.isEmpty());
Assert.assertTrue(bm.getWidth() == 0);
Assert.assertTrue(bm.getHeight() == 0);
Assert.assertTrue(bm.getSize() == 0);
}
/**
* This method detects a Data Matrix code in a "pure" image -- that is, pure monochrome image
* which contains only an unrotated, unskewed, image of a Data Matrix code, with some white border
* around it. This is a specialized method that works exceptionally fast in this special case.
*/
private static BitMatrix extractPureBits(BitMatrix image) throws NotFoundException {
// Now need to determine module size in pixels
int height = image.getHeight();
int width = image.getWidth();
int minDimension = Math.min(height, width);
// First, skip white border by tracking diagonally from the top left down and to the right:
int borderWidth = 0;
while (borderWidth < minDimension && !image.get(borderWidth, borderWidth)) {
borderWidth++;
}
if (borderWidth == minDimension) {
throw NotFoundException.getNotFoundInstance();
}
// And then keep tracking across the top-left black module to determine module size
int moduleEnd = borderWidth + 1;
while (moduleEnd < width && image.get(moduleEnd, borderWidth)) {
moduleEnd++;
}
if (moduleEnd == width) {
throw NotFoundException.getNotFoundInstance();
}
int moduleSize = moduleEnd - borderWidth;
// And now find where the bottommost black module on the first column ends
int columnEndOfSymbol = height - 1;
while (columnEndOfSymbol >= 0 && !image.get(borderWidth, columnEndOfSymbol)) {
columnEndOfSymbol--;
}
if (columnEndOfSymbol < 0) {
throw NotFoundException.getNotFoundInstance();
}
columnEndOfSymbol++;
// Make sure width of barcode is a multiple of module size
if ((columnEndOfSymbol - borderWidth) % moduleSize != 0) {
throw NotFoundException.getNotFoundInstance();
}
int dimension = (columnEndOfSymbol - borderWidth) / moduleSize;
// Push in the "border" by half the module width so that we start
// sampling in the middle of the module. Just in case the image is a
// little off, this will help recover.
borderWidth += moduleSize >> 1;
int sampleDimension = borderWidth + (dimension - 1) * moduleSize;
if (sampleDimension >= width || sampleDimension >= height) {
throw NotFoundException.getNotFoundInstance();
}
// Now just read off the bits
BitMatrix bits = new BitMatrix(dimension);
for (int i = 0; i < dimension; i++) {
int iOffset = borderWidth + i * moduleSize;
for (int j = 0; j < dimension; j++) {
if (image.get(borderWidth + j * moduleSize, iOffset)) {
bits.set(j, i);
}
}
}
return bits;
}
