import com.google.zxing.BarcodeFormat;
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import com.google.zxing.BinaryBitmap;
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import com.google.zxing.DecodeHintType;
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import com.google.zxing.LuminanceSource;
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import com.google.zxing.MultiFormatReader;
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import com.google.zxing.Result;
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import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
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import com.google.zxing.common.HybridBinarizer;
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import javax.imageio.ImageIO;
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import java.awt.RenderingHints;
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import java.awt.image.BufferedImage;
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import java.io.File;
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import java.util.EnumMap;
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import java.util.List;
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import java.util.Map;
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/**
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* 解码失败样本的成因判定
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*
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* 用法：java DiagnoseQrFailures <标签目录> <文件名1> [文件名2 ...]
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*
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* 思路：把图片按整数倍最近邻放大后重新解码。二维码是纯黑白方块，
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* 最近邻放大不引入新信息，只是给解码器的采样网格更多余地。
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* - 放大后能解出 → 二维码数据本身是对的，只是模块密度/采样位置过于临界
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* （属解码端问题，但印刷尺寸偏小时真实扫码枪也可能读不出，应缩短二维码内容或加大标签）
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* - 放大后仍解不出 → 该标签确有缺陷，需按废品处理
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*/
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public class DiagnoseQrFailures {
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public static void main(String[] args) throws Exception {
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File dir = new File(args[0]);
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for (int i = 1; i < args.length; i++) {
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File f = new File(dir, args[i]);
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if (!f.isFile()) {
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System.out.println(args[i] + " -> 文件不存在");
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continue;
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}
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BufferedImage img = ImageIO.read(f);
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String at1 = decode(img);
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System.out.println("\n=== " + args[i] + " ===");
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System.out.println(" 原始尺寸 : " + img.getWidth() + " x " + img.getHeight());
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System.out.println(" 1x 解码 : " + (at1 == null ? "失败" : "成功 -> " + at1));
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if (at1 != null) {
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continue;
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}
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boolean rescued = false;
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for (int scale : List.of(2, 3, 4, 6)) {
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BufferedImage up = scaleNearest(img, scale);
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String text = decode(up);
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System.out.println(" " + scale + "x 放大解码 : " + (text == null ? "失败" : "成功 -> " + text));
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if (text != null) {
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rescued = true;
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break;
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}
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}
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System.out.println(" 结论 : " + (rescued
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? "二维码数据有效，属模块密度临界（解码端），非废码"
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: "放大后仍不可识读，标签确有缺陷"));
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}
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}
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/** 整数倍最近邻放大：不插值、不引入新像素值，只放大采样空间 */
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private static BufferedImage scaleNearest(BufferedImage src, int scale) {
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BufferedImage out = new BufferedImage(
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src.getWidth() * scale, src.getHeight() * scale, BufferedImage.TYPE_INT_RGB);
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var g = out.createGraphics();
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try {
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g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR);
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g.drawImage(src, 0, 0, out.getWidth(), out.getHeight(), null);
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} finally {
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g.dispose();
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}
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return out;
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}
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private static String decode(BufferedImage image) {
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LuminanceSource source = new BufferedImageLuminanceSource(image);
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Map<DecodeHintType, Object> hints = new EnumMap<>(DecodeHintType.class);
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hints.put(DecodeHintType.CHARACTER_SET, "UTF-8");
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hints.put(DecodeHintType.TRY_HARDER, Boolean.TRUE);
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hints.put(DecodeHintType.POSSIBLE_FORMATS, List.of(BarcodeFormat.QR_CODE));
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try {
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Result r = new MultiFormatReader().decode(
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new BinaryBitmap(new HybridBinarizer(source)), hints);
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return r == null ? null : r.getText();
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} catch (Exception e) {
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return null;
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}
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}
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}
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