/*
- * Copyright 2007 Google Inc.
+ * Copyright 2008 ZXing authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
package com.google.zxing.client.j2se;
-import com.google.zxing.BlackPointEstimationMethod;
import com.google.zxing.MonochromeBitmapSource;
-import com.google.zxing.ReaderException;
-import com.google.zxing.common.BitArray;
-import com.google.zxing.common.BlackPointEstimator;
+import com.google.zxing.common.BaseMonochromeBitmapSource;
import java.awt.geom.AffineTransform;
import java.awt.image.AffineTransformOp;
* based on a region of a {@link BufferedImage}; see
* {@link #BufferedImageMonochromeBitmapSource(BufferedImage, int, int, int, int)}.</p>
*
- * @author srowen@google.com (Sean Owen), Daniel Switkin (dswitkin@google.com)
+ * @author Sean Owen
+ * @author Daniel Switkin (dswitkin@google.com)
*/
-public final class BufferedImageMonochromeBitmapSource implements MonochromeBitmapSource {
+public final class BufferedImageMonochromeBitmapSource extends BaseMonochromeBitmapSource {
private final BufferedImage image;
private final int left;
private final int top;
- private final int width;
- private final int height;
- private int blackPoint;
- private BlackPointEstimationMethod lastMethod;
- private int lastArgument;
-
- private static final int LUMINANCE_BITS = 5;
- private static final int LUMINANCE_SHIFT = 8 - LUMINANCE_BITS;
- private static final int LUMINANCE_BUCKETS = 1 << LUMINANCE_BITS;
/**
* Creates an instance that uses the entire given image as a source of pixels to decode.
* @param image image to decode a region of
* @param left x coordinate of leftmost pixels to decode
* @param top y coordinate of topmost pixels to decode
- * @param right one more than the x coordinate of rightmost pixels to decode. That is, we will decode
+ * @param right one more than the x coordinate of rightmost pixels to decode, i.e. we will decode
* pixels whose x coordinate is in [left,right)
* @param bottom likewise, one more than the y coordinate of the bottommost pixels to decode
*/
- public BufferedImageMonochromeBitmapSource(BufferedImage image, int left, int top, int right, int bottom) {
+ public BufferedImageMonochromeBitmapSource(BufferedImage image, int left, int top, int right,
+ int bottom) {
+ super(right - left, bottom - top);
this.image = image;
- blackPoint = 0x7F;
- lastMethod = null;
- lastArgument = 0;
int sourceHeight = image.getHeight();
int sourceWidth = image.getWidth();
- if (left < 0 || top < 0 || right > sourceWidth || bottom > sourceHeight || right <= left || bottom <= top) {
- throw new IllegalArgumentException("Invalid bounds: (" + top + ',' + left + ") (" + right + ',' + bottom + ')');
+ if (left < 0 || top < 0 || right > sourceWidth || bottom > sourceHeight || right <= left ||
+ bottom <= top) {
+ throw new IllegalArgumentException("Invalid bounds: (" + top + ',' + left + ") (" + right +
+ ',' + bottom + ')');
}
this.left = left;
this.top = top;
- this.width = right - left;
- this.height = bottom - top;
}
/**
* @return underlying {@link BufferedImage} behind this instance. Note that even if this instance
- * only uses a subset of the full image, the returned value here represents the entire backing image.
+ * only uses a subset of the full image, the returned value here represents the entire backing
+ * image.
*/
public BufferedImage getImage() {
return image;
}
- private int getRGB(int x, int y) {
- return image.getRGB(left + x, top + y);
- }
-
- private void getRGBRow(int startX, int startY, int[] result) {
- image.getRGB(left + startX, top + startY, result.length, 1, result, 0, result.length);
- }
-
- public boolean isBlack(int x, int y) {
- return computeRGBLuminance(getRGB(x, y)) < blackPoint;
- }
-
- public BitArray getBlackRow(int y, BitArray row, int startX, int getWidth) {
- if (row == null || row.getSize() < getWidth) {
- row = new BitArray(getWidth);
- } else {
- row.clear();
- }
- int[] pixelRow = new int[getWidth];
- getRGBRow(startX, y, pixelRow);
-
- // If the current decoder calculated the blackPoint based on one row, assume we're trying to
- // decode a 1D barcode, and apply some sharpening.
- // TODO: We may want to add a fifth parameter to request the amount of shapening to be done.
- if (lastMethod == BlackPointEstimationMethod.ROW_SAMPLING) {
- int left = computeRGBLuminance(pixelRow[0]);
- int center = computeRGBLuminance(pixelRow[1]);
- for (int i = 1; i < getWidth - 1; i++) {
- int right = computeRGBLuminance(pixelRow[i + 1]);
- // Simple -1 4 -1 box filter with a weight of 2
- int luminance = ((center << 2) - left - right) >> 1;
- if (luminance < blackPoint) {
- row.set(i);
- }
- left = center;
- center = right;
- }
- } else {
- for (int i = 0; i < getWidth; i++) {
- if (computeRGBLuminance(pixelRow[i]) < blackPoint) {
- row.set(i);
- }
- }
- }
- return row;
- }
-
- public int getHeight() {
- return height;
- }
-
- public int getWidth() {
- return width;
- }
-
- public void estimateBlackPoint(BlackPointEstimationMethod method, int argument) throws ReaderException {
- if (!method.equals(lastMethod) || argument != lastArgument) {
- int[] histogram = new int[LUMINANCE_BUCKETS];
- if (method.equals(BlackPointEstimationMethod.TWO_D_SAMPLING)) {
- int minDimension = width < height ? width : height;
- int startI = height == minDimension ? 0 : (height - width) >> 1;
- int startJ = width == minDimension ? 0 : (width - height) >> 1;
- for (int n = 0; n < minDimension; n++) {
- int pixel = getRGB(startJ + n, startI + n);
- histogram[computeRGBLuminance(pixel) >> LUMINANCE_SHIFT]++;
- }
- } else if (method.equals(BlackPointEstimationMethod.ROW_SAMPLING)) {
- if (argument < 0 || argument >= height) {
- throw new IllegalArgumentException("Row is not within the image: " + argument);
- }
- int[] rgbArray = new int[width];
- getRGBRow(0, argument, rgbArray);
- for (int x = 0; x < width; x++) {
- histogram[computeRGBLuminance(rgbArray[x]) >> LUMINANCE_SHIFT]++;
- }
- } else {
- throw new IllegalArgumentException("Unknown method: " + method);
- }
- blackPoint = BlackPointEstimator.estimate(histogram) << LUMINANCE_SHIFT;
- lastMethod = method;
- lastArgument = argument;
- }
- }
-
- public BlackPointEstimationMethod getLastEstimationMethod() {
- return lastMethod;
- }
-
+ @Override
public MonochromeBitmapSource rotateCounterClockwise() {
if (!isRotateSupported()) {
throw new IllegalStateException("Rotate not supported");
}
int sourceWidth = image.getWidth();
int sourceHeight = image.getHeight();
+
// 90 degrees counterclockwise:
AffineTransform transform = new AffineTransform(0.0, -1.0, 1.0, 0.0, 0.0, sourceWidth);
BufferedImageOp op = new AffineTransformOp(transform, AffineTransformOp.TYPE_NEAREST_NEIGHBOR);
+
// Note width/height are flipped since we are rotating 90 degrees:
BufferedImage rotatedImage = new BufferedImage(sourceHeight, sourceWidth, image.getType());
op.filter(image, rotatedImage);
return new BufferedImageMonochromeBitmapSource(rotatedImage,
top,
- sourceWidth - (left + width),
- top + height,
+ sourceWidth - (left + getWidth()),
+ top + getHeight(),
sourceWidth - left);
}
+ @Override
public boolean isRotateSupported() {
// Can't run AffineTransforms on images of unknown format
return image.getType() != BufferedImage.TYPE_CUSTOM;
*
* where R, G, and B are values in [0,1].
*/
- private static int computeRGBLuminance(int pixel) {
+ @Override
+ protected int getLuminance(int x, int y) {
+ int pixel = image.getRGB(left + x, top + y);
// Coefficients add up to 1024 to make the divide into a fast shift
return (306 * ((pixel >> 16) & 0xFF) +
601 * ((pixel >> 8) & 0xFF) +
117 * (pixel & 0xFF)) >> 10;
}
+ @Override
+ protected int[] getLuminanceRow(int y, int[] row) {
+ int width = getWidth();
+ if (row == null || row.length < width) {
+ row = new int[width];
+ }
+ image.getRGB(left, top + y, width, 1, row, 0, width);
+ for (int x = 0; x < width; x++) {
+ int pixel = row[x];
+ row[x] = (306 * ((pixel >> 16) & 0xFF) +
+ 601 * ((pixel >> 8) & 0xFF) +
+ 117 * (pixel & 0xFF)) >> 10;
+ }
+ return row;
+ }
+
+ @Override
+ protected int[] getLuminanceColumn(int x, int[] column) {
+ int height = getHeight();
+ if (column == null || column.length < height) {
+ column = new int[height];
+ }
+ image.getRGB(left + x, top, 1, height, column, 0, 1);
+ for (int y = 0; y < height; y++) {
+ int pixel = column[y];
+ column[y] = (306 * ((pixel >> 16) & 0xFF) +
+ 601 * ((pixel >> 8) & 0xFF) +
+ 117 * (pixel & 0xFF)) >> 10;
+ }
+ return column;
+ }
+
}
projects / zxing.git / blobdiff