java多种方法实现图片OCR示例代码

以下是一个使用Java多种方法实现图片OCR的示例代码：

1. 使用Tesseract OCR库：

import net.sourceforge.tess4j.*;

public class ImageOCR {
    public static void main(String[] args) {
        File imageFile = new File("image.png");
        ITesseract instance = new Tesseract();
        try {
            String result = instance.doOCR(imageFile);
            System.out.println(result);
        } catch (TesseractException e) {
            System.err.println(e.getMessage());
        }
    }
}

2. 使用Google Cloud Vision API：

import com.google.cloud.vision.v1.*;
import com.google.protobuf.ByteString;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

public class ImageOCR {
    public static void main(String[] args) throws IOException {
        Path imagePath = Paths.get("image.png");
        byte[] imageBytes = Files.readAllBytes(imagePath);
        ByteString byteString = ByteString.copyFrom(imageBytes);

        try (ImageAnnotatorClient client = ImageAnnotatorClient.create()) {
            Image image = Image.newBuilder().setContent(byteString).build();
            AnnotateImageRequest request = AnnotateImageRequest.newBuilder()
                    .addFeatures(Feature.newBuilder().setType(Feature.Type.TEXT_DETECTION))
                    .setImage(image)
                    .build();
            BatchAnnotateImagesResponse response = client.batchAnnotateImages(ImmutableList.of(request));
            TextAnnotation textAnnotation = response.getResponses(0).getFullTextAnnotation();
            System.out.println(textAnnotation.getText());
        }
    }
}

3. 使用OpenCV和Tesseract OCR库：

import org.opencv.core.*;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
import net.sourceforge.tess4j.*;

public class ImageOCR {
    public static void main(String[] args) {
        System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
        Mat image = Imgcodecs.imread("image.png");
        Mat gray = new Mat();
        Imgproc.cvtColor(image, gray, Imgproc.COLOR_BGR2GRAY);
        Imgproc.threshold(gray, gray, 0, 255, Imgproc.THRESH_BINARY | Imgproc.THRESH_OTSU);
        ITesseract instance = new Tesseract();
        try {
            String result = instance.doOCR(gray);
            System.out.println(result);
        } catch (TesseractException e) {
            System.err.println(e.getMessage());
        }
    }
}