rxing/pdf417/decoder/
pdf_417_codeword_decoder.rs

1/*
2 * Copyright 2013 ZXing authors
3 *
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
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
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.
15 */
16
17use crate::pdf417::pdf_417_common;
18
19/*
20 * @author Guenther Grau
21 * @author creatale GmbH (christoph.schulz@creatale.de)
22 */
23
24static RATIOS_TABLE: [[f32; pdf_417_common::BARS_IN_MODULE as usize]; 2787] = {
25    let mut table =
26        [[0.0; pdf_417_common::BARS_IN_MODULE as usize]; pdf_417_common::SYMBOL_TABLE.len()];
27    // Pre-computes the symbol ratio table.
28    let mut i = 0_usize;
29    while i < pdf_417_common::SYMBOL_TABLE.len() {
30        // for (int i = 0; i < PDF417Common.SYMBOL_TABLE.length; i++) {
31        let mut currentSymbol = pdf_417_common::SYMBOL_TABLE[i];
32        let mut currentBit = currentSymbol & 0x1;
33        let mut j = 0_usize;
34        while j < pdf_417_common::BARS_IN_MODULE as usize {
35            // for (int j = 0; j < pdf_417_common::BARS_IN_MODULE; j++) {
36            let mut size = 0.0;
37            while (currentSymbol & 0x1) == currentBit {
38                size += 1.0;
39                currentSymbol >>= 1;
40            }
41            currentBit = currentSymbol & 0x1;
42            table[i][pdf_417_common::BARS_IN_MODULE as usize - j - 1] =
43                size / pdf_417_common::MODULES_IN_CODEWORD as f32;
44
45            j += 1;
46        }
47
48        i += 1;
49    }
50
51    table
52};
53
54pub fn getDecodedValue(moduleBitCount: &[u32]) -> u32 {
55    let decodedValue = getDecodedCodewordValue(&sampleBitCounts(moduleBitCount));
56    if decodedValue != -1 {
57        return decodedValue as u32;
58    }
59    getClosestDecodedValue(moduleBitCount) as u32
60}
61
62fn sampleBitCounts(moduleBitCount: &[u32]) -> [u32; 8] {
63    let bitCountSum: u32 = moduleBitCount.iter().sum(); //MathUtils.sum(moduleBitCount);
64    let mut result = [0; pdf_417_common::BARS_IN_MODULE as usize];
65    let mut bitCountIndex = 0;
66    let mut sumPreviousBits = 0;
67    for i in 0..pdf_417_common::MODULES_IN_CODEWORD {
68        // for (int i = 0; i < PDF417Common.MODULES_IN_CODEWORD; i++) {
69        let sampleIndex: f32 = bitCountSum as f32
70            / (2.0 * pdf_417_common::MODULES_IN_CODEWORD as f32)
71            + (i as f32 * bitCountSum as f32) / pdf_417_common::MODULES_IN_CODEWORD as f32;
72        if sumPreviousBits as f32 + moduleBitCount[bitCountIndex] as f32 <= sampleIndex {
73            sumPreviousBits += moduleBitCount[bitCountIndex];
74            bitCountIndex += 1;
75        }
76        result[bitCountIndex] += 1;
77    }
78    result
79}
80
81fn getDecodedCodewordValue(moduleBitCount: &[u32]) -> i32 {
82    let decodedValue = getBitValue(moduleBitCount);
83    if pdf_417_common::getCodeword(decodedValue as u32) == -1 {
84        -1
85    } else {
86        decodedValue
87    }
88}
89
90fn getBitValue(moduleBitCount: &[u32]) -> i32 {
91    let mut result: u64 = 0;
92    for (i, mbc) in moduleBitCount.iter().enumerate() {
93        // for (int i = 0; i < moduleBitCount.length; i++) {
94        for _bit in 0..(*mbc) {
95            // for (int bit = 0; bit < moduleBitCount[i]; bit++) {
96            result = (result << 1) | u64::from(i % 2 == 0); //(if i % 2 == 0 { 1 } else { 0 });
97        }
98    }
99    result as i32
100}
101
102fn getClosestDecodedValue(moduleBitCount: &[u32]) -> i32 {
103    let bitCountSum: u32 = moduleBitCount.iter().sum(); //MathUtils.sum(moduleBitCount);
104    let mut bitCountRatios = [0.0; pdf_417_common::BARS_IN_MODULE as usize];
105    if bitCountSum > 1 {
106        for i in 0..bitCountRatios.len() {
107            // for (int i = 0; i < bitCountRatios.length; i++) {
108            bitCountRatios[i] = moduleBitCount[i] as f32 / bitCountSum as f32;
109        }
110    }
111    let mut bestMatchError = f32::MAX;
112    let mut bestMatch = -1_i32;
113    for (j, ratioTableRow) in RATIOS_TABLE.iter().enumerate() {
114        // for (int j = 0; j < RATIOS_TABLE.length; j++) {
115        let mut error = 0.0;
116        for k in 0..pdf_417_common::BARS_IN_MODULE as usize {
117            // for (int k = 0; k < PDF417Common.BARS_IN_MODULE; k++) {
118            let diff = ratioTableRow[k] - bitCountRatios[k];
119            error += diff * diff;
120            if error >= bestMatchError {
121                break;
122            }
123        }
124        if error < bestMatchError {
125            bestMatchError = error;
126            bestMatch = pdf_417_common::SYMBOL_TABLE[j] as i32;
127        }
128    }
129    bestMatch
130}
131
132#[cfg(test)]
133mod test {
134    use crate::pdf417::decoder::pdf_417_codeword_decoder::getDecodedValue;
135
136    #[test]
137    fn test_cw_227() {
138        let sample_data = [2, 2, 3, 1, 6, 4, 3, 4];
139        assert_ne!(getDecodedValue(&sample_data), 110360);
140        assert_eq!(getDecodedValue(&sample_data), 93980);
141    }
142
143    #[test]
144    fn test_2() {
145        let sample = [2, 1, 4, 2, 5, 3, 7, 2];
146        assert_ne!(95134, getDecodedValue(&sample));
147    }
148
149    #[test]
150    fn test_128268() {
151        let sample = [7, 2, 1, 2, 2, 5, 3, 3];
152        assert_eq!(128268, getDecodedValue(&sample));
153    }
154
155    #[test]
156    fn test_125304() {
157        let sample = [6, 1, 2, 2, 2, 2, 6, 4];
158        assert_eq!(125304, getDecodedValue(&sample));
159    }
160
161    #[test]
162    fn test_125216() {
163        let sample = [6, 1, 2, 2, 2, 3, 2, 7];
164        assert_eq!(125216, getDecodedValue(&sample));
165    }
166
167    #[test]
168    fn test_83768() {
169        let sample = [1, 2, 1, 4, 5, 3, 5, 4];
170        assert_eq!(83768, getDecodedValue(&sample));
171    }
172
173    #[test]
174    fn test_96060() {
175        let sample = [2, 1, 4, 2, 5, 3, 7, 2];
176        assert_eq!(96060, getDecodedValue(&sample));
177    }
178
179    #[test]
180    fn test_97372() {
181        let sample = [3, 1, 7, 4, 2, 2, 4, 2];
182        assert_eq!(97372, getDecodedValue(&sample));
183    }
184}
rxing/pdf417/decoder/pdf_417_codeword_decoder.rs

rxing/pdf417/decoder/
pdf_417_codeword_decoder.rs
