*/
public final class MaskUtil {
+ private MaskUtil() {
+ // do nothing
+ }
+
// The mask penalty calculation is complicated. See Table 21 of JISX0510:2004 (p.45) for details.
// Basically it applies four rules and summate all penalties.
- public static int CalculateMaskPenalty(final ByteMatrix matrix) {
+ public static int calculateMaskPenalty(final ByteMatrix matrix) {
int penalty = 0;
- penalty += ApplyMaskPenaltyRule1(matrix);
- penalty += ApplyMaskPenaltyRule2(matrix);
- penalty += ApplyMaskPenaltyRule3(matrix);
- penalty += ApplyMaskPenaltyRule4(matrix);
+ penalty += applyMaskPenaltyRule1(matrix);
+ penalty += applyMaskPenaltyRule2(matrix);
+ penalty += applyMaskPenaltyRule3(matrix);
+ penalty += applyMaskPenaltyRule4(matrix);
return penalty;
}
// Apply mask penalty rule 1 and return the penalty. Find repetitive cells with the same color and
// give penalty to them. Example: 00000 or 11111.
- public static int ApplyMaskPenaltyRule1(final ByteMatrix matrix) {
- final int penalty = (ApplyMaskPenaltyRule1Internal(matrix, true) +
- ApplyMaskPenaltyRule1Internal(matrix, false));
- Debug.LOG_INFO("\tApplyMaskPenaltyRule1: " + penalty);
- return penalty;
+ public static int applyMaskPenaltyRule1(final ByteMatrix matrix) {
+ return applyMaskPenaltyRule1Internal(matrix, true) + applyMaskPenaltyRule1Internal(matrix, false);
}
// Apply mask penalty rule 2 and return the penalty. Find 2x2 blocks with the same color and give
// penalty to them.
- //
- // JAVAPORT: Consider using ByteMatrix.getArray() instead.
- public static int ApplyMaskPenaltyRule2(final ByteMatrix matrix) {
+ public static int applyMaskPenaltyRule2(final ByteMatrix matrix) {
int penalty = 0;
- for (int y = 0; y < matrix.height() - 1; ++y) {
- for (int x = 0; x < matrix.width() - 1; ++x) {
- int value = matrix.get(y, x);
- if (value == matrix.get(y + 0, x + 1) &&
- value == matrix.get(y + 1, x + 0) &&
- value == matrix.get(y + 1, x + 1)) {
+ byte[][] array = matrix.getArray();
+ int width = matrix.width();
+ int height = matrix.height();
+ for (int y = 0; y < height - 1; ++y) {
+ for (int x = 0; x < width - 1; ++x) {
+ int value = array[y][x];
+ if (value == array[y][x + 1] && value == array[y + 1][x] && value == array[y + 1][x + 1]) {
penalty += 3;
}
}
}
- Debug.LOG_INFO("\tApplyMaskPenaltyRule2: " + penalty);
return penalty;
}
// Apply mask penalty rule 3 and return the penalty. Find consecutive cells of 00001011101 or
// 10111010000, and give penalty to them. If we find patterns like 000010111010000, we give
// penalties twice (i.e. 40 * 2).
- //
- // JAVAPORT: This many calls to ByteMatrix.get() looks expensive. We should profile and consider
- // adding a byte[][] ByteMatrix.getArray() method, then using that array locally.
- public static int ApplyMaskPenaltyRule3(final ByteMatrix matrix) {
+ public static int applyMaskPenaltyRule3(final ByteMatrix matrix) {
int penalty = 0;
- for (int y = 0; y < matrix.height(); ++y) {
- for (int x = 0; x < matrix.width(); ++x) {
+ byte[][] array = matrix.getArray();
+ int width = matrix.width();
+ int height = matrix.height();
+ for (int y = 0; y < height; ++y) {
+ for (int x = 0; x < width; ++x) {
// Tried to simplify following conditions but failed.
- if (x + 6 < matrix.width() &&
- matrix.get(y, x + 0) == 1 &&
- matrix.get(y, x + 1) == 0 &&
- matrix.get(y, x + 2) == 1 &&
- matrix.get(y, x + 3) == 1 &&
- matrix.get(y, x + 4) == 1 &&
- matrix.get(y, x + 5) == 0 &&
- matrix.get(y, x + 6) == 1 &&
- ((x + 10 < matrix.width() &&
- matrix.get(y, x + 7) == 0 &&
- matrix.get(y, x + 8) == 0 &&
- matrix.get(y, x + 9) == 0 &&
- matrix.get(y, x + 10) == 0) ||
+ if (x + 6 < width &&
+ array[y][x] == 1 &&
+ array[y][x + 1] == 0 &&
+ array[y][x + 2] == 1 &&
+ array[y][x + 3] == 1 &&
+ array[y][x + 4] == 1 &&
+ array[y][x + 5] == 0 &&
+ array[y][x + 6] == 1 &&
+ ((x + 10 < width &&
+ array[y][x + 7] == 0 &&
+ array[y][x + 8] == 0 &&
+ array[y][x + 9] == 0 &&
+ array[y][x + 10] == 0) ||
(x - 4 >= 0 &&
- matrix.get(y, x - 1) == 0 &&
- matrix.get(y, x - 2) == 0 &&
- matrix.get(y, x - 3) == 0 &&
- matrix.get(y, x - 4) == 0))) {
+ array[y][x - 1] == 0 &&
+ array[y][x - 2] == 0 &&
+ array[y][x - 3] == 0 &&
+ array[y][x - 4] == 0))) {
penalty += 40;
}
- if (y + 6 < matrix.height() &&
- matrix.get(y + 0, x) == 1 &&
- matrix.get(y + 1, x) == 0 &&
- matrix.get(y + 2, x) == 1 &&
- matrix.get(y + 3, x) == 1 &&
- matrix.get(y + 4, x) == 1 &&
- matrix.get(y + 5, x) == 0 &&
- matrix.get(y + 6, x) == 1 &&
- ((y + 10 < matrix.height() &&
- matrix.get(y + 7, x) == 0 &&
- matrix.get(y + 8, x) == 0 &&
- matrix.get(y + 9, x) == 0 &&
- matrix.get(y + 10, x) == 0) ||
+ if (y + 6 < height &&
+ array[y][x] == 1 &&
+ array[y + 1][x] == 0 &&
+ array[y + 2][x] == 1 &&
+ array[y + 3][x] == 1 &&
+ array[y + 4][x] == 1 &&
+ array[y + 5][x] == 0 &&
+ array[y + 6][x] == 1 &&
+ ((y + 10 < height &&
+ array[y + 7][x] == 0 &&
+ array[y + 8][x] == 0 &&
+ array[y + 9][x] == 0 &&
+ array[y + 10][x] == 0) ||
(y - 4 >= 0 &&
- matrix.get(y - 1, x) == 0 &&
- matrix.get(y - 2, x) == 0 &&
- matrix.get(y - 3, x) == 0 &&
- matrix.get(y - 4, x) == 0))) {
+ array[y - 1][x] == 0 &&
+ array[y - 2][x] == 0 &&
+ array[y - 3][x] == 0 &&
+ array[y - 4][x] == 0))) {
penalty += 40;
}
}
}
- Debug.LOG_INFO("\tApplyMaskPenaltyRule3: " + penalty);
return penalty;
}
// - 55% => 10
// - 55% => 20
// - 100% => 100
- public static int ApplyMaskPenaltyRule4(final ByteMatrix matrix) {
- int num_dark_cells = 0;
- for (int y = 0; y < matrix.height(); ++y) {
- for (int x = 0; x < matrix.width(); ++x) {
- if (matrix.get(y, x) == 1) {
- num_dark_cells += 1;
+ public static int applyMaskPenaltyRule4(final ByteMatrix matrix) {
+ int numDarkCells = 0;
+ byte[][] array = matrix.getArray();
+ int width = matrix.width();
+ int height = matrix.height();
+ for (int y = 0; y < height; ++y) {
+ for (int x = 0; x < width; ++x) {
+ if (array[y][x] == 1) {
+ numDarkCells += 1;
}
}
}
- final int num_total_cells = matrix.height() * matrix.width();
- double dark_ratio = (double) num_dark_cells / num_total_cells;
- final int penalty = Math.abs((int) (dark_ratio * 100 - 50)) / 5 * 10;
- Debug.LOG_INFO("\tApplyMaskPenaltyRule4: " + penalty);
- return penalty;
+ final int numTotalCells = matrix.height() * matrix.width();
+ double darkRatio = (double) numDarkCells / numTotalCells;
+ return Math.abs((int) (darkRatio * 100 - 50)) / 5 * 10;
}
- // Return the mask bit for "mask_pattern" at "x" and "y". See 8.8 of JISX0510:2004 for mask
+ // Return the mask bit for "getMaskPattern" at "x" and "y". See 8.8 of JISX0510:2004 for mask
// pattern conditions.
- public static int GetDataMaskBit(final int mask_pattern, final int x, final int y) {
- Debug.DCHECK(QRCode.IsValidMaskPattern(mask_pattern));
- switch (mask_pattern) {
+ public static int getDataMaskBit(final int maskPattern, final int x, final int y) {
+ if (!QRCode.isValidMaskPattern(maskPattern)) {
+ throw new IllegalArgumentException("Invalid mask pattern");
+ }
+ switch (maskPattern) {
case 0:
return ((y + x) % 2 == 0) ? 1 : 0;
case 1:
return ((((y * x) % 2) + ((y * x) % 3)) % 2 == 0) ? 1 : 0;
case 7:
return ((((y * x) % 3) + ((y + x) % 2)) % 2 == 0) ? 1 : 0;
- default:
- ;
}
- Debug.LOG_ERROR("invalid mask pattern: " + mask_pattern);
- return -1;
+ throw new IllegalArgumentException("invalid mask pattern: " + maskPattern);
}
- // Helper function for ApplyMaskPenaltyRule1. We need this for doing this calculation in both
+ // Helper function for applyMaskPenaltyRule1. We need this for doing this calculation in both
// vertical and horizontal orders respectively.
- private static int ApplyMaskPenaltyRule1Internal(final ByteMatrix matrix, boolean is_horizontal) {
+ private static int applyMaskPenaltyRule1Internal(final ByteMatrix matrix, boolean isHorizontal) {
int penalty = 0;
- int num_same_bit_cells = 0;
- int prev_bit = -1;
+ int numSameBitCells = 0;
+ int prevBit = -1;
// Horizontal mode:
// for (int i = 0; i < matrix.height(); ++i) {
// for (int j = 0; j < matrix.width(); ++j) {
// for (int i = 0; i < matrix.width(); ++i) {
// for (int j = 0; j < matrix.height(); ++j) {
// int bit = matrix.get(j, i);
- final int i_limit = is_horizontal ? matrix.height() : matrix.width();
- final int j_limit = is_horizontal ? matrix.width() : matrix.height();
- for (int i = 0; i < i_limit; ++i) {
- for (int j = 0; j < j_limit; ++j) {
- final int bit = is_horizontal ? matrix.get(i, j) : matrix.get(j, i);
- if (bit == prev_bit) {
- num_same_bit_cells += 1;
+ final int iLimit = isHorizontal ? matrix.height() : matrix.width();
+ final int jLimit = isHorizontal ? matrix.width() : matrix.height();
+ byte[][] array = matrix.getArray();
+ for (int i = 0; i < iLimit; ++i) {
+ for (int j = 0; j < jLimit; ++j) {
+ final int bit = isHorizontal ? array[i][j] : array[j][i];
+ if (bit == prevBit) {
+ numSameBitCells += 1;
// Found five repetitive cells with the same color (bit).
// We'll give penalty of 3.
- if (num_same_bit_cells == 5) {
+ if (numSameBitCells == 5) {
penalty += 3;
- } else if (num_same_bit_cells > 5) {
+ } else if (numSameBitCells > 5) {
// After five repetitive cells, we'll add the penalty one
// by one.
penalty += 1;
}
} else {
- num_same_bit_cells = 1; // Include the cell itself.
- prev_bit = bit;
+ numSameBitCells = 1; // Include the cell itself.
+ prevBit = bit;
}
}
- num_same_bit_cells = 0; // Clear at each row/column.
+ numSameBitCells = 0; // Clear at each row/column.
}
return penalty;
}
projects / zxing.git / blobdiff