/*
* 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.
*/
using System;
using System.Collections.Generic;
using ZXing.Common;
using ZXing.Multi;
using ZXing.PDF417.Internal;
namespace ZXing.PDF417
{
/// <summary>
/// This implementation can detect and decode PDF417 codes in an image.
///
/// <author>SITA Lab ([email protected])</author>
/// <author>Guenther Grau</author>
/// </summary>
public sealed class PDF417Reader : Reader, MultipleBarcodeReader
{
/// <summary>
/// Locates and decodes a PDF417 code in an image.
///
/// <returns>a String representing the content encoded by the PDF417 code</returns>
/// <exception cref="FormatException">if a PDF417 cannot be decoded</exception>
/// </summary>
public Result decode(BinaryBitmap image)
{
return decode(image, null);
}
/// <summary>
/// Locates and decodes a barcode in some format within an image. This method also accepts
/// hints, each possibly associated to some data, which may help the implementation decode.
/// **Note** this will return the FIRST barcode discovered if there are many.
/// </summary>
/// <param name="image">image of barcode to decode</param>
/// <param name="hints">passed as a <see cref="IDictionary{TKey, TValue}"/> from
/// to arbitrary data. The
/// meaning of the data depends upon the hint type. The implementation may or may not do
/// anything with these hints.</param>
/// <returns>
/// String which the barcode encodes
/// </returns>
public Result decode(BinaryBitmap image,
IDictionary<DecodeHintType, object> hints)
{
Result[] results = decode(image, hints, false);
if (results.Length == 0)
{
return null;
}
else
{
return results[0]; // First barcode discovered.
}
}
/// <summary>
/// Locates and decodes Multiple PDF417 codes in an image.
///
/// <returns>an array of Strings representing the content encoded by the PDF417 codes</returns>
/// </summary>
public Result[] decodeMultiple(BinaryBitmap image)
{
return decodeMultiple(image, null);
}
/// <summary>
/// Locates and decodes multiple barcodes in some format within an image. This method also accepts
/// hints, each possibly associated to some data, which may help the implementation decode.
/// </summary>
/// <param name="image">image of barcode to decode</param>
/// <param name="hints">passed as a <see cref="IDictionary{TKey, TValue}"/> from
/// to arbitrary data. The
/// meaning of the data depends upon the hint type. The implementation may or may not do
/// anything with these hints.</param>
/// <returns>
/// String which the barcodes encode
/// </returns>
public Result[] decodeMultiple(BinaryBitmap image,
IDictionary<DecodeHintType, object> hints)
{
return decode(image, hints, true);
}
/// <summary>
/// Decode the specified image, with the hints and optionally multiple barcodes.
/// Based on Owen's Comments in <see cref="ZXing.ReaderException"/>, this method has been modified to continue silently
/// if a barcode was not decoded where it was detected instead of throwing a new exception object.
/// </summary>
/// <param name="image">Image.</param>
/// <param name="hints">Hints.</param>
/// <param name="multiple">If set to <c>true multiple.
private static Result[] decode(BinaryBitmap image, IDictionary<DecodeHintType, object> hints, bool multiple)
{
var results = new List<Result>();
var detectorResult = Detector.detect(image, hints, multiple);
if (detectorResult != null)
{
foreach (var points in detectorResult.Points)
{
var decoderResult = PDF417ScanningDecoder.decode(detectorResult.Bits, points[4], points[5],
points[6], points[7], getMinCodewordWidth(points), getMaxCodewordWidth(points));
if (decoderResult == null)
{
continue;
}
var result = new Result(decoderResult.Text, decoderResult.RawBytes, points, BarcodeFormat.PDF_417);
result.putMetadata(ResultMetadataType.ERROR_CORRECTION_LEVEL, decoderResult.ECLevel);
var pdf417ResultMetadata = (PDF417ResultMetadata) decoderResult.Other;
if (pdf417ResultMetadata != null)
{
result.putMetadata(ResultMetadataType.PDF417_EXTRA_METADATA, pdf417ResultMetadata);
}
results.Add(result);
}
}
return results.ToArray();
}
/// <summary>
/// Gets the maximum width of the barcode
/// </summary>
/// <returns>The max width.</returns>
/// <param name="p1">P1.</param>
/// <param name="p2">P2.</param>
private static int getMaxWidth(ResultPoint p1, ResultPoint p2)
{
if (p1 == null || p2 == null)
{
return 0;
}
return (int) Math.Abs(p1.X - p2.X);
}
/// <summary>
/// Gets the minimum width of the barcode
/// </summary>
/// <returns>The minimum width.</returns>
/// <param name="p1">P1.</param>
/// <param name="p2">P2.</param>
private static int getMinWidth(ResultPoint p1, ResultPoint p2)
{
if (p1 == null || p2 == null)
{
return int.MaxValue;
}
return (int) Math.Abs(p1.X - p2.X);
}
/// <summary>
/// Gets the maximum width of the codeword.
/// </summary>
/// <returns>The max codeword width.</returns>
/// <param name="p">P.</param>
private static int getMaxCodewordWidth(ResultPoint[] p)
{
return Math.Max(
Math.Max(getMaxWidth(p[0], p[4]), getMaxWidth(p[6], p[2])*PDF417Common.MODULES_IN_CODEWORD/
PDF417Common.MODULES_IN_STOP_PATTERN),
Math.Max(getMaxWidth(p[1], p[5]), getMaxWidth(p[7], p[3])*PDF417Common.MODULES_IN_CODEWORD/
PDF417Common.MODULES_IN_STOP_PATTERN));
}
/// <summary>
/// Gets the minimum width of the codeword.
/// </summary>
/// <returns>The minimum codeword width.</returns>
/// <param name="p">P.</param>
private static int getMinCodewordWidth(ResultPoint[] p)
{
return Math.Min(
Math.Min(getMinWidth(p[0], p[4]), getMinWidth(p[6], p[2])*PDF417Common.MODULES_IN_CODEWORD/
PDF417Common.MODULES_IN_STOP_PATTERN),
Math.Min(getMinWidth(p[1], p[5]), getMinWidth(p[7], p[3])*PDF417Common.MODULES_IN_CODEWORD/
PDF417Common.MODULES_IN_STOP_PATTERN));
}
/// <summary>
/// Resets any internal state the implementation has after a decode, to prepare it
/// for reuse.
/// </summary>
public void reset()
{
// do nothing
}
}
}
