-/*\r
+/*\r
+* Copyright 2008 ZXing authors\r
+*\r
* Licensed under the Apache License, Version 2.0 (the "License");\r
* you may not use this file except in compliance with the License.\r
* You may obtain a copy of the License at\r
* See the License for the specific language governing permissions and\r
* limitations under the License.\r
*/\r
+using System;\r
+using ReaderException = com.google.zxing.ReaderException;\r
+using Result = com.google.zxing.Result;\r
+using ResultPointCallback = com.google.zxing.ResultPointCallback;\r
+using DecodeHintType = com.google.zxing.DecodeHintType;\r
+using ResultPoint = com.google.zxing.ResultPoint;\r
+using BarcodeFormat = com.google.zxing.BarcodeFormat;\r
+using BitArray = com.google.zxing.common.BitArray;\r
namespace com.google.zxing.oned\r
{\r
- using com.google.zxing.common; \r
- /**\r
- * <p>This interfaces captures addtional functionality that readers of\r
- * UPC/EAN family of barcodes should expose.</p>\r
- *\r
- * @author Sean Owen\r
- */\r
-\r
- public interface UPCEANReader : OneDReader \r
- {\r
- /**\r
- * <p>Like {@link #decodeRow(int, BitArray, java.util.Hashtable)}, but\r
- * allows caller to inform method about where the UPC/EAN start pattern is\r
- * found. This allows this to be computed once and reused across many implementations.</p>\r
- */\r
- Result decodeRow(int rowNumber, BitArray row, int[] startGuardRange);\r
- }\r
-\r
+ \r
+ /// <summary> <p>Encapsulates functionality and implementation that is common to UPC and EAN families\r
+ /// of one-dimensional barcodes.</p>\r
+ /// \r
+ /// </summary>\r
+ /// <author> dswitkin@google.com (Daniel Switkin)\r
+ /// </author>\r
+ /// <author> Sean Owen\r
+ /// </author>\r
+ /// <author> alasdair@google.com (Alasdair Mackintosh)\r
+ /// </author>\r
+ /// <author>www.Redivivus.in (suraj.supekar@redivivus.in) - Ported from ZXING Java Source \r
+ /// </author>\r
+ public abstract class UPCEANReader:OneDReader\r
+ {\r
+ /// <summary> Get the format of this decoder.\r
+ /// \r
+ /// </summary>\r
+ /// <returns> The 1D format.\r
+ /// </returns>\r
+ internal abstract BarcodeFormat BarcodeFormat{get;}\r
+ \r
+ // These two values are critical for determining how permissive the decoding will be.\r
+ // We've arrived at these values through a lot of trial and error. Setting them any higher\r
+ // lets false positives creep in quickly.\r
+ //UPGRADE_NOTE: Final was removed from the declaration of 'MAX_AVG_VARIANCE '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"\r
+ //UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"\r
+ private static readonly int MAX_AVG_VARIANCE = (int) (PATTERN_MATCH_RESULT_SCALE_FACTOR * 0.42f);\r
+ //UPGRADE_NOTE: Final was removed from the declaration of 'MAX_INDIVIDUAL_VARIANCE '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"\r
+ //UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"\r
+ private static readonly int MAX_INDIVIDUAL_VARIANCE = (int) (PATTERN_MATCH_RESULT_SCALE_FACTOR * 0.7f);\r
+ \r
+ /// <summary> Start/end guard pattern.</summary>\r
+ //UPGRADE_NOTE: Final was removed from the declaration of 'START_END_PATTERN'. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"\r
+ internal static readonly int[] START_END_PATTERN = new int[]{1, 1, 1};\r
+ \r
+ /// <summary> Pattern marking the middle of a UPC/EAN pattern, separating the two halves.</summary>\r
+ //UPGRADE_NOTE: Final was removed from the declaration of 'MIDDLE_PATTERN'. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"\r
+ internal static readonly int[] MIDDLE_PATTERN = new int[]{1, 1, 1, 1, 1};\r
+ \r
+ /// <summary> "Odd", or "L" patterns used to encode UPC/EAN digits.</summary>\r
+ //UPGRADE_NOTE: Final was removed from the declaration of 'L_PATTERNS'. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"\r
+ internal static readonly int[][] L_PATTERNS = new int[][]{new int[]{3, 2, 1, 1}, new int[]{2, 2, 2, 1}, new int[]{2, 1, 2, 2}, new int[]{1, 4, 1, 1}, new int[]{1, 1, 3, 2}, new int[]{1, 2, 3, 1}, new int[]{1, 1, 1, 4}, new int[]{1, 3, 1, 2}, new int[]{1, 2, 1, 3}, new int[]{3, 1, 1, 2}};\r
+ \r
+ /// <summary> As above but also including the "even", or "G" patterns used to encode UPC/EAN digits.</summary>\r
+ internal static int[][] L_AND_G_PATTERNS;\r
+ \r
+ //UPGRADE_NOTE: Final was removed from the declaration of 'decodeRowStringBuffer '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"\r
+ private System.Text.StringBuilder decodeRowStringBuffer;\r
+ \r
+ protected internal UPCEANReader()\r
+ {\r
+ decodeRowStringBuffer = new System.Text.StringBuilder(20);\r
+ }\r
+ \r
+ internal static int[] findStartGuardPattern(BitArray row)\r
+ {\r
+ bool foundStart = false;\r
+ int[] startRange = null;\r
+ int nextStart = 0;\r
+ while (!foundStart)\r
+ {\r
+ startRange = findGuardPattern(row, nextStart, false, START_END_PATTERN);\r
+ int start = startRange[0];\r
+ nextStart = startRange[1];\r
+ // Make sure there is a quiet zone at least as big as the start pattern before the barcode.\r
+ // If this check would run off the left edge of the image, do not accept this barcode,\r
+ // as it is very likely to be a false positive.\r
+ int quietStart = start - (nextStart - start);\r
+ if (quietStart >= 0)\r
+ {\r
+ foundStart = row.isRange(quietStart, start, false);\r
+ }\r
+ }\r
+ return startRange;\r
+ }\r
+ \r
+ public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable hints)\r
+ {\r
+ return decodeRow(rowNumber, row, findStartGuardPattern(row), hints);\r
+ }\r
+ \r
+ /// <summary> <p>Like {@link #decodeRow(int, BitArray, java.util.Hashtable)}, but\r
+ /// allows caller to inform method about where the UPC/EAN start pattern is\r
+ /// found. This allows this to be computed once and reused across many implementations.</p>\r
+ /// </summary>\r
+ public virtual Result decodeRow(int rowNumber, BitArray row, int[] startGuardRange, System.Collections.Hashtable hints)\r
+ {\r
+ \r
+ ResultPointCallback resultPointCallback = hints == null?null:(ResultPointCallback) hints[DecodeHintType.NEED_RESULT_POINT_CALLBACK];\r
+ \r
+ if (resultPointCallback != null)\r
+ {\r
+ resultPointCallback.foundPossibleResultPoint(new ResultPoint((startGuardRange[0] + startGuardRange[1]) / 2.0f, rowNumber));\r
+ }\r
+ \r
+ System.Text.StringBuilder result = decodeRowStringBuffer;\r
+ result.Length = 0;\r
+ int endStart = decodeMiddle(row, startGuardRange, result);\r
+ \r
+ if (resultPointCallback != null)\r
+ {\r
+ resultPointCallback.foundPossibleResultPoint(new ResultPoint(endStart, rowNumber));\r
+ }\r
+ \r
+ int[] endRange = decodeEnd(row, endStart);\r
+ \r
+ if (resultPointCallback != null)\r
+ {\r
+ resultPointCallback.foundPossibleResultPoint(new ResultPoint((endRange[0] + endRange[1]) / 2.0f, rowNumber));\r
+ }\r
+ \r
+ \r
+ // Make sure there is a quiet zone at least as big as the end pattern after the barcode. The\r
+ // spec might want more whitespace, but in practice this is the maximum we can count on.\r
+ int end = endRange[1];\r
+ int quietEnd = end + (end - endRange[0]);\r
+ if (quietEnd >= row.Size || !row.isRange(end, quietEnd, false))\r
+ {\r
+ throw ReaderException.Instance;\r
+ }\r
+ \r
+ System.String resultString = result.ToString();\r
+ if (!checkChecksum(resultString))\r
+ {\r
+ throw ReaderException.Instance;\r
+ }\r
+ \r
+ //UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"\r
+ float left = (float) (startGuardRange[1] + startGuardRange[0]) / 2.0f;\r
+ //UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"\r
+ float right = (float) (endRange[1] + endRange[0]) / 2.0f;\r
+ //UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"\r
+ return new Result(resultString, null, new ResultPoint[]{new ResultPoint(left, (float) rowNumber), new ResultPoint(right, (float) rowNumber)}, BarcodeFormat);\r
+ }\r
+ \r
+ /// <returns> {@link #checkStandardUPCEANChecksum(String)}\r
+ /// </returns>\r
+ //UPGRADE_NOTE: Access modifiers of method 'checkChecksum' were changed to 'protected'. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1204'"\r
+ protected internal virtual bool checkChecksum(System.String s)\r
+ {\r
+ return checkStandardUPCEANChecksum(s);\r
+ }\r
+ \r
+ /// <summary> Computes the UPC/EAN checksum on a string of digits, and reports\r
+ /// whether the checksum is correct or not.\r
+ /// \r
+ /// </summary>\r
+ /// <param name="s">string of digits to check\r
+ /// </param>\r
+ /// <returns> true iff string of digits passes the UPC/EAN checksum algorithm\r
+ /// </returns>\r
+ /// <throws> ReaderException if the string does not contain only digits </throws>\r
+ private static bool checkStandardUPCEANChecksum(System.String s)\r
+ {\r
+ int length = s.Length;\r
+ if (length == 0)\r
+ {\r
+ return false;\r
+ }\r
+ \r
+ int sum = 0;\r
+ for (int i = length - 2; i >= 0; i -= 2)\r
+ {\r
+ int digit = (int) s[i] - (int) '0';\r
+ if (digit < 0 || digit > 9)\r
+ {\r
+ throw ReaderException.Instance;\r
+ }\r
+ sum += digit;\r
+ }\r
+ sum *= 3;\r
+ for (int i = length - 1; i >= 0; i -= 2)\r
+ {\r
+ int digit = (int) s[i] - (int) '0';\r
+ if (digit < 0 || digit > 9)\r
+ {\r
+ throw ReaderException.Instance;\r
+ }\r
+ sum += digit;\r
+ }\r
+ return sum % 10 == 0;\r
+ }\r
+ \r
+ //UPGRADE_NOTE: Access modifiers of method 'decodeEnd' were changed to 'protected'. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1204'"\r
+ protected internal virtual int[] decodeEnd(BitArray row, int endStart)\r
+ {\r
+ return findGuardPattern(row, endStart, false, START_END_PATTERN);\r
+ }\r
+ \r
+ /// <param name="row">row of black/white values to search\r
+ /// </param>\r
+ /// <param name="rowOffset">position to start search\r
+ /// </param>\r
+ /// <param name="whiteFirst">if true, indicates that the pattern specifies white/black/white/...\r
+ /// pixel counts, otherwise, it is interpreted as black/white/black/...\r
+ /// </param>\r
+ /// <param name="pattern">pattern of counts of number of black and white pixels that are being\r
+ /// searched for as a pattern\r
+ /// </param>\r
+ /// <returns> start/end horizontal offset of guard pattern, as an array of two ints\r
+ /// </returns>\r
+ /// <throws> ReaderException if pattern is not found </throws>\r
+ internal static int[] findGuardPattern(BitArray row, int rowOffset, bool whiteFirst, int[] pattern)\r
+ {\r
+ int patternLength = pattern.Length;\r
+ int[] counters = new int[patternLength];\r
+ int width = row.Size;\r
+ bool isWhite = false;\r
+ while (rowOffset < width)\r
+ {\r
+ isWhite = !row.get_Renamed(rowOffset);\r
+ if (whiteFirst == isWhite)\r
+ {\r
+ break;\r
+ }\r
+ rowOffset++;\r
+ }\r
+ \r
+ int counterPosition = 0;\r
+ int patternStart = rowOffset;\r
+ for (int x = rowOffset; x < width; x++)\r
+ {\r
+ bool pixel = row.get_Renamed(x);\r
+ if (pixel ^ isWhite)\r
+ {\r
+ counters[counterPosition]++;\r
+ }\r
+ else\r
+ {\r
+ if (counterPosition == patternLength - 1)\r
+ {\r
+ if (patternMatchVariance(counters, pattern, MAX_INDIVIDUAL_VARIANCE) < MAX_AVG_VARIANCE)\r
+ {\r
+ return new int[]{patternStart, x};\r
+ }\r
+ patternStart += counters[0] + counters[1];\r
+ for (int y = 2; y < patternLength; y++)\r
+ {\r
+ counters[y - 2] = counters[y];\r
+ }\r
+ counters[patternLength - 2] = 0;\r
+ counters[patternLength - 1] = 0;\r
+ counterPosition--;\r
+ }\r
+ else\r
+ {\r
+ counterPosition++;\r
+ }\r
+ counters[counterPosition] = 1;\r
+ isWhite = !isWhite;\r
+ }\r
+ }\r
+ throw ReaderException.Instance;\r
+ }\r
+ \r
+ /// <summary> Attempts to decode a single UPC/EAN-encoded digit.\r
+ /// \r
+ /// </summary>\r
+ /// <param name="row">row of black/white values to decode\r
+ /// </param>\r
+ /// <param name="counters">the counts of runs of observed black/white/black/... values\r
+ /// </param>\r
+ /// <param name="rowOffset">horizontal offset to start decoding from\r
+ /// </param>\r
+ /// <param name="patterns">the set of patterns to use to decode -- sometimes different encodings\r
+ /// for the digits 0-9 are used, and this indicates the encodings for 0 to 9 that should\r
+ /// be used\r
+ /// </param>\r
+ /// <returns> horizontal offset of first pixel beyond the decoded digit\r
+ /// </returns>\r
+ /// <throws> ReaderException if digit cannot be decoded </throws>\r
+ internal static int decodeDigit(BitArray row, int[] counters, int rowOffset, int[][] patterns)\r
+ {\r
+ recordPattern(row, rowOffset, counters);\r
+ int bestVariance = MAX_AVG_VARIANCE; // worst variance we'll accept\r
+ int bestMatch = - 1;\r
+ int max = patterns.Length;\r
+ for (int i = 0; i < max; i++)\r
+ {\r
+ int[] pattern = patterns[i];\r
+ int variance = patternMatchVariance(counters, pattern, MAX_INDIVIDUAL_VARIANCE);\r
+ if (variance < bestVariance)\r
+ {\r
+ bestVariance = variance;\r
+ bestMatch = i;\r
+ }\r
+ }\r
+ if (bestMatch >= 0)\r
+ {\r
+ return bestMatch;\r
+ }\r
+ else\r
+ {\r
+ throw ReaderException.Instance;\r
+ }\r
+ }\r
+ \r
+ /// <summary> Subclasses override this to decode the portion of a barcode between the start\r
+ /// and end guard patterns.\r
+ /// \r
+ /// </summary>\r
+ /// <param name="row">row of black/white values to search\r
+ /// </param>\r
+ /// <param name="startRange">start/end offset of start guard pattern\r
+ /// </param>\r
+ /// <param name="resultString">{@link StringBuffer} to append decoded chars to\r
+ /// </param>\r
+ /// <returns> horizontal offset of first pixel after the "middle" that was decoded\r
+ /// </returns>\r
+ /// <throws> ReaderException if decoding could not complete successfully </throws>\r
+ protected internal abstract int decodeMiddle(BitArray row, int[] startRange, System.Text.StringBuilder resultString);\r
+ static UPCEANReader()\r
+ {\r
+ {\r
+ L_AND_G_PATTERNS = new int[20][];\r
+ for (int i = 0; i < 10; i++)\r
+ {\r
+ L_AND_G_PATTERNS[i] = L_PATTERNS[i];\r
+ }\r
+ for (int i = 10; i < 20; i++)\r
+ {\r
+ int[] widths = L_PATTERNS[i - 10];\r
+ int[] reversedWidths = new int[widths.Length];\r
+ for (int j = 0; j < widths.Length; j++)\r
+ {\r
+ reversedWidths[j] = widths[widths.Length - j - 1];\r
+ }\r
+ L_AND_G_PATTERNS[i] = reversedWidths;\r
+ }\r
+ }\r
+ }\r
+ }\r
}
\ No newline at end of file
projects / zxing.git / blobdiff