Dynamsoft Barcode Reader SDK一款多功能的條碼讀取控件，只需要幾行代碼就可以將條碼讀取功能嵌入到Web或桌面應(yīng)用程序。這可以節(jié)省數(shù)月的開(kāi)發(fā)時(shí)間和成本。能支持多種圖像文件格式以及從攝像機(jī)或掃描儀獲取的DIB格式。使用Dynamsoft Barcode Reader SDK，你可以創(chuàng)建強(qiáng)大且實(shí)用的條形碼掃描儀軟件，以滿足你的業(yè)務(wù)需求。

點(diǎn)擊下載Dynamsoft Barcode Reader最新版

許多企業(yè)喜歡使用Dynamsoft Barcode Reader SDK，因?yàn)樗哂徐`活的參數(shù)配置和強(qiáng)大的對(duì)多個(gè)條形碼的解碼能力。在本文中，讓我們看一下條形碼SDK模板以及從開(kāi)發(fā)人員的角度優(yōu)化解碼性能的可能方法。

如何配置用于解碼性能的模板

如果您從未嘗試過(guò)Dynamsoft Barcode Reader SDK，則可以在在線條形碼游樂(lè)場(chǎng)玩耍，只需更改模式即可直接比較性能差異。

此外，如果您是專家，則可以單擊高級(jí)設(shè)置自行調(diào)整一系列參數(shù)。

為了方便開(kāi)發(fā)人員，我向Github上傳了五個(gè)有用的模板文件：

• Speed.json
• Balanced.json
• Coverage.json
• Morecoverage.json
• Mostcoverage.json

這是我的測(cè)試圖像：

我們來(lái)看一下使用不同模板的檢測(cè)準(zhǔn)確性和時(shí)間成本：

BarcodeReader.exe AllSupportedBarcodeTypes.png  license.txt  speed.json   
Total barcode(s) found: 12. Time cost: 63 ms

BarcodeReader.exe AllSupportedBarcodeTypes.png  license.txt   balanced.json
Total barcode(s) found: 13. Time cost: 140 ms
 
BarcodeReader.exe AllSupportedBarcodeTypes.png  license.txt   coverage.json
Total barcode(s) found: 13. Time cost: 844 ms
 
BarcodeReader.exe AllSupportedBarcodeTypes.png  license.txt   morecoverage.json
Total barcode(s) found: 13. Time cost: 1610 ms
 
BarcodeReader.exe AllSupportedBarcodeTypes.png  license.txt   mostcoverage.json
Total barcode(s) found: 13. Time cost: 3156 ms

使用多線程可以加快多條形碼解碼的性能嗎？

按照我們的常識(shí)，解碼單個(gè)條形碼的時(shí)間成本應(yīng)小于解碼多個(gè)條形碼的時(shí)間成本。因此，讀取多個(gè)條形碼的一種可能的優(yōu)化方法是創(chuàng)建多個(gè)工作線程，以同時(shí)處理不同的條形碼符號(hào)。

這是用于順序解碼一維和二維條形碼的代碼：

barcode_decoding(buffer, size, BF_CODE_39, 1, license, config);
barcode_decoding(buffer, size, BF_QR_CODE, 1, license, config);
barcode_decoding(buffer, size, BF_PDF417, 1, license, config);
barcode_decoding(buffer, size, BF_DATAMATRIX, 1, license, config);

Thread id: 22536. Type: CODE_39
Thread id: 22536. Total barcode(s) found: 1. Time cost: 235 ms
 
Thread id: 22536. Type: QR_CODE
Thread id: 22536. Total barcode(s) found: 1. Time cost: 47 ms
 
Thread id: 22536. Type: PDF417
Thread id: 22536. Total barcode(s) found: 1. Time cost: 62 ms
 
Thread id: 22536. Type: DATAMATRIX
Thread id: 22536. Total barcode(s) found: 1. Time cost: 63 ms

int starttime = gettime();
thread t1(barcode_decoding, buffer, size, BF_CODE_39, 1, license, config); 
thread t2(barcode_decoding, buffer, size, BF_QR_CODE, 1, license, config);
thread t3(barcode_decoding, buffer, size, BF_PDF417, 1, license, config);
thread t4(barcode_decoding, buffer, size, BF_DATAMATRIX, 1, license, config);
t1.join();
t2.join();
t3.join();
t4.join();
int endtime = gettime();
printf("Thread time cost: %d ms\n\n", (endtime - starttime));

Thread id: 24024. Type: QR_CODE
Thread id: 24024. Total barcode(s) found: 1. Time cost: 78 ms
 
Thread id: 17384. Type: DATAMATRIX
Thread id: 17384. Total barcode(s) found: 1. Time cost: 78 ms
 
Thread id: 24264. Type: PDF417
Thread id: 24264. Total barcode(s) found: 1. Time cost: 94 ms
 
Thread id: 4060. Type: CODE_39
Thread id: 4060. Total barcode(s) found: 1. Time cost: 265 ms
 
Thread time cost: 265 ms

barcode_decoding(buffer, size, BF_CODE_39 | BF_DATAMATRIX | BF_QR_CODE | BF_PDF417, 1, license, config);

Thread id: 20308. Type: PDF417
Thread id: 20308. Type: QR_CODE
Thread id: 20308. Type: DATAMATRIX
Thread id: 20308. Type: CODE_39
Thread id: 20308. Total barcode(s) found: 4. Time cost: 250 ms

您可能已經(jīng)注意到，有一個(gè)名為maxAlgorithmThreadCount的參數(shù)。我們可以通過(guò)增加線程數(shù)來(lái)提高SDK性能嗎？

我根據(jù)硬件線程做了一個(gè)簡(jiǎn)單的測(cè)試：

const auto processor_count = std::thread::hardware_concurrency();
int minimum_count = 1, minimum_timecost = 0;
    for (int i = 0; i < processor_count; i++) 
    {
        printf("Thread count: %d. ", i + 1);
        int timecost = barcode_decoding(buffer, size, formats, i, license, config);
        if (i == 0) 
        {
            minimum_count = 1; 
            if (timecost > 0)
            {
                minimum_timecost = timecost; 
            }
        }
        else {
            if (timecost < minimum_timecost)
            {
                minimum_count = i + 1;
                minimum_timecost = timecost; 
            }
        }
    }
    printf("Multi-thread best performance: thread_count = %d, timecost = %d \n\n", minimum_count, minimum_timecost);

Thread count: 1. Thread id: 26376. Total barcode(s) found: 13. Time cost: 141 ms
 
Thread count: 2. Thread id: 26376. Total barcode(s) found: 13. Time cost: 141 ms
 
Thread count: 3. Thread id: 26376. Total barcode(s) found: 13. Time cost: 125 ms
 
Thread count: 4. Thread id: 26376. Total barcode(s) found: 13. Time cost: 140 ms
 
Thread count: 5. Thread id: 26376. Total barcode(s) found: 13. Time cost: 157 ms
 
Thread count: 6. Thread id: 26376. Total barcode(s) found: 13. Time cost: 203 ms
 
Thread count: 7. Thread id: 26376. Total barcode(s) found: 13. Time cost: 156 ms
 
Thread count: 8. Thread id: 26376. Total barcode(s) found: 13. Time cost: 140 ms
 
Multi-thread best performance: thread_count = 3, timecost = 125