zxing/csharp/BinaryBitmap.cs

using System.Collections;

/*
 * Copyright 2009 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

namespace com.google.zxing
{

	using BitArray = com.google.zxing.common.BitArray;
	using BitMatrix = com.google.zxing.common.BitMatrix;

	/// <summary>
	/// This class is the core bitmap class used by ZXing to represent 1 bit data. Reader objects
	/// accept a BinaryBitmap and attempt to decode it.
	/// 
	/// @author dswitkin@google.com (Daniel Switkin)
	/// </summary>
	public sealed class BinaryBitmap
	{

	  private readonly Binarizer binarizer;
	  private BitMatrix matrix;

	  public BinaryBitmap(Binarizer binarizer)
	  {
		if (binarizer == null)
		{
		  throw new System.ArgumentException("Binarizer must be non-null.");
		}
		this.binarizer = binarizer;
	  }

	  /// <returns> The width of the bitmap. </returns>
	  public int Width
	  {
		  get
		  {
			return binarizer.Width;
		  }
	  }

	  /// <returns> The height of the bitmap. </returns>
	  public int Height
	  {
		  get
		  {
			return binarizer.Height;
		  }
	  }

	  /// <summary>
	  /// Converts one row of luminance data to 1 bit data. May actually do the conversion, or return
	  /// cached data. Callers should assume this method is expensive and call it as seldom as possible.
	  /// This method is intended for decoding 1D barcodes and may choose to apply sharpening.
	  /// </summary>
	  /// <param name="y"> The row to fetch, 0 <= y < bitmap height. </param>
	  /// <param name="row"> An optional preallocated array. If null or too small, it will be ignored.
	  ///            If used, the Binarizer will call BitArray.clear(). Always use the returned object. </param>
	  /// <returns> The array of bits for this row (true means black). </returns>
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in .NET:
//ORIGINAL LINE: public com.google.zxing.common.BitArray getBlackRow(int y, com.google.zxing.common.BitArray row) throws NotFoundException
	  public BitArray getBlackRow(int y, BitArray row)
	  {
		return binarizer.getBlackRow(y, row);
	  }

	  /// <summary>
	  /// Converts a 2D array of luminance data to 1 bit. As above, assume this method is expensive
	  /// and do not call it repeatedly. This method is intended for decoding 2D barcodes and may or
	  /// may not apply sharpening. Therefore, a row from this matrix may not be identical to one
	  /// fetched using getBlackRow(), so don't mix and match between them.
	  /// </summary>
	  /// <returns> The 2D array of bits for the image (true means black). </returns>
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in .NET:
//ORIGINAL LINE: public com.google.zxing.common.BitMatrix getBlackMatrix() throws NotFoundException
	  public BitMatrix BlackMatrix
	  {
		  get
		  {
			// The matrix is created on demand the first time it is requested, then cached. There are two
			// reasons for this:
			// 1. This work will never be done if the caller only installs 1D Reader objects, or if a
			//    1D Reader finds a barcode before the 2D Readers run.
			// 2. This work will only be done once even if the caller installs multiple 2D Readers.
			if (matrix == null)
			{
			  matrix = binarizer.BlackMatrix;
			}
			return matrix;
		  }
	  }

	  /// <returns> Whether this bitmap can be cropped. </returns>
	  public bool CropSupported
	  {
		  get
		  {
			return binarizer.LuminanceSource.CropSupported;
		  }
	  }

	  /// <summary>
	  /// Returns a new object with cropped image data. Implementations may keep a reference to the
	  /// original data rather than a copy. Only callable if isCropSupported() is true.
	  /// </summary>
	  /// <param name="left"> The left coordinate, 0 <= left < getWidth(). </param>
	  /// <param name="top"> The top coordinate, 0 <= top <= getHeight(). </param>
	  /// <param name="width"> The width of the rectangle to crop. </param>
	  /// <param name="height"> The height of the rectangle to crop. </param>
	  /// <returns> A cropped version of this object. </returns>
	  public BinaryBitmap crop(int left, int top, int width, int height)
	  {
		LuminanceSource newSource = binarizer.LuminanceSource.crop(left, top, width, height);
		return new BinaryBitmap(binarizer.createBinarizer(newSource));
	  }

	  /// <returns> Whether this bitmap supports counter-clockwise rotation. </returns>
	  public bool RotateSupported
	  {
		  get
		  {
			return binarizer.LuminanceSource.RotateSupported;
		  }
	  }

	  /// <summary>
	  /// Returns a new object with rotated image data by 90 degrees counterclockwise.
	  /// Only callable if <seealso cref="#isRotateSupported()"/> is true.
	  /// </summary>
	  /// <returns> A rotated version of this object. </returns>
	  public BinaryBitmap rotateCounterClockwise()
	  {
		LuminanceSource newSource = binarizer.LuminanceSource.rotateCounterClockwise();
		return new BinaryBitmap(binarizer.createBinarizer(newSource));
	  }

	  /// <summary>
	  /// Returns a new object with rotated image data by 45 degrees counterclockwise.
	  /// Only callable if <seealso cref="#isRotateSupported()"/> is true.
	  /// </summary>
	  /// <returns> A rotated version of this object. </returns>
	  public BinaryBitmap rotateCounterClockwise45()
	  {
		LuminanceSource newSource = binarizer.LuminanceSource.rotateCounterClockwise45();
		return new BinaryBitmap(binarizer.createBinarizer(newSource));
	  }

	}

}