2 * Copyright 2007 ZXing authors
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 package com.google.zxing;
19 import com.google.zxing.common.BitArray;
22 * <p>Encapsulates a generic black-and-white bitmap -- a collection of pixels in two dimensions.
23 * This unifies many possible representations, like AWT's <code>BufferedImage</code>.</p>
25 * @author srowen@google.com (Sean Owen)
26 * @author dswitkin@google.com (Daniel Switkin)
28 public interface MonochromeBitmapSource {
31 * @param x horizontal offset, from left, of the pixel
32 * @param y vertical offset, from top, of the pixel
33 * @return true iff the pixel at (x,y) is black
35 boolean isBlack(int x, int y);
38 * <p>Returns an entire row of black/white pixels as an array of bits, where "true" means "black".
39 * This is a sort of "bulk get" operation intended to enable efficient access in
40 * certain situations.</p>
42 * @param y vertical offset, from top, of the row of pixels
43 * @param row if not null, {@link BitArray} to write pixels into. If null, a new {@link BitArray}
44 * is allocated and returned.
45 * @param startX horizontal offset, from left, from which to start getting pixels
46 * @param getWidth number of pixels to get from the row
47 * @return {@link BitArray} representing the (subset of the) row of pixels. If row parameter
48 * was not null, it is returned.
50 BitArray getBlackRow(int y, BitArray row, int startX, int getWidth);
53 * Entirely analogous to {@link #getBlackRow(int, BitArray, int, int)} but gets a column.
55 BitArray getBlackColumn(int x, BitArray column, int startY, int getHeight);
58 * @return height of underlying image
63 * @return width of underlying image
68 * <p>Estimates black point according to the given method, which is optionally parameterized by
69 * a single int argument. For {@link BlackPointEstimationMethod#ROW_SAMPLING}, this
70 * specifies the row to sample.</p>
72 * <p>The estimated value will be used in subsequent computations that rely on an estimated black
75 * @param method black point estimation method
76 * @param argument method-specific argument
78 void estimateBlackPoint(BlackPointEstimationMethod method, int argument) throws ReaderException;
81 * @return {@link BlackPointEstimationMethod} representing last sampling method used
83 BlackPointEstimationMethod getLastEstimationMethod();
86 * <p>Optional operation which returns an implementation based on the same underlying
87 * image, but which behaves as if the underlying image had been rotated 90 degrees
88 * counterclockwise. This is useful in the context of 1D barcodes and the
89 * {@link DecodeHintType#TRY_HARDER} decode hint, and is only intended to be
90 * used in non-resource-constrained environments. Hence, implementations
91 * of this class which are only used in resource-constrained mobile environments
92 * don't have a need to implement this.</p>
94 * @throws IllegalArgumentException if not supported
96 MonochromeBitmapSource rotateCounterClockwise();
99 * @return true iff rotation is supported
100 * @see #rotateCounterClockwise()
102 boolean isRotateSupported();