Esempio n. 1
0
        internal static Version DecodeVersionInformation(int versionBits)
        {
            int bestDifference = Int32.MaxValue;
            int bestVersion    = 0;

            for (int i = 0; i < VERSION_DECODE_INFO.Length; i++)
            {
                int targetVersion = VERSION_DECODE_INFO[i];
                // Do the version info bits match exactly? done.
                if (targetVersion == versionBits)
                {
                    return(GetVersionForNumber(i + 7));
                }
                // Otherwise see if this is the closest to a real version info bit string
                // we have seen so far
                int bitsDifference = FormatInformation.NumBitsDiffering(versionBits, targetVersion);
                if (bitsDifference < bestDifference)
                {
                    bestVersion    = i + 7;
                    bestDifference = bitsDifference;
                }
            }
            // We can tolerate up to 3 bits of error since no two version info codewords will
            // differ in less than 8 bits.
            if (bestDifference <= 3)
            {
                return(GetVersionForNumber(bestVersion));
            }
            // If we didn't find a close enough match, fail
            return(null);
        }
Esempio n. 2
0
        /// <summary>
        /// Decodes the format information.
        /// </summary>
        /// <param name="maskedFormatInfo1">format info indicator, with mask still applied</param>
        /// <param name="maskedFormatInfo2">The masked format info2.</param>
        /// <returns>
        /// information about the format it specifies, or <code>null</code>
        /// if doesn't seem to match any known pattern
        /// </returns>
        internal static FormatInformation DecodeFormatInformation(int maskedFormatInfo1, int maskedFormatInfo2)
        {
            FormatInformation formatInfo = DoDecodeFormatInformation(maskedFormatInfo1, maskedFormatInfo2);

            if (formatInfo != null)
            {
                return(formatInfo);
            }
            // Should return null, but, some QR codes apparently
            // do not mask this info. Try again by actually masking the pattern
            // first
            return(DoDecodeFormatInformation(maskedFormatInfo1 ^ FORMAT_INFO_MASK_QR,
                                             maskedFormatInfo2 ^ FORMAT_INFO_MASK_QR));
        }