Java调用OCR进行图片识别

使用Java语言，通过Tesseract-OCR对图片进行识别。

1.Tesseract-OCR

下载windows版本并安装。

2.程序如下：

a.ImageIOHelper类

package OCR;

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.Locale;

import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.metadata.IIOMetadata;
import javax.imageio.stream.ImageInputStream;
import javax.imageio.stream.ImageOutputStream;

import com.sun.media.imageio.plugins.tiff.TIFFImageWriteParam;

public class ImageIOHelper {
	/**
	 * 图片文件转换为tif格式
	 * @param imageFile 文件路径
	 * @param imageFormat 文件扩展名
	 * @return
	 */
	public static File createImage(File imageFile, String imageFormat) {
		File tempFile = null;
		try {
			Iterator<ImageReader> readers = ImageIO.getImageReadersByFormatName(imageFormat);
			ImageReader reader = readers.next();
		
			ImageInputStream iis = ImageIO.createImageInputStream(imageFile);
			reader.setInput(iis);
			//Read the stream metadata
			IIOMetadata streamMetadata = reader.getStreamMetadata();
			
			//Set up the writeParam
			TIFFImageWriteParam tiffWriteParam = new TIFFImageWriteParam(Locale.CHINESE);
			tiffWriteParam.setCompressionMode(ImageWriteParam.MODE_DISABLED);
			
			//Get tif writer and set output to file
			Iterator<ImageWriter> writers = ImageIO.getImageWritersByFormatName("tiff");
			ImageWriter writer = writers.next();
			
			BufferedImage bi = reader.read(0);
			IIOImage image = new IIOImage(bi,null,reader.getImageMetadata(0));
			tempFile = tempImageFile(imageFile);
			ImageOutputStream ios = ImageIO.createImageOutputStream(tempFile);
			writer.setOutput(ios);
			writer.write(streamMetadata, image, tiffWriteParam);
			ios.close();
			
			writer.dispose();
			reader.dispose();
			
		} catch (IOException e) {
			e.printStackTrace();
		}
		return tempFile;
	}

	private static File tempImageFile(File imageFile) {
		String path = imageFile.getPath();
		StringBuffer strB = new StringBuffer(path);
		strB.insert(path.lastIndexOf('.'),0);
		return new File(strB.toString().replaceFirst("(?<=//.)(//w+)$", "tif"));
	}

}

b.OCR核心类

package OCR;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

import org.jdesktop.swingx.util.OS;

public class OCR {
	private final String LANG_OPTION = "-l";  //英文字母小写l，并非数字1
	private final String EOL = System.getProperty("line.separator");
	private String tessPath = "C://Program Files//Tesseract-OCR";
	//private String tessPath = new File("tesseract").getAbsolutePath();
	
	public String recognizeText(File imageFile,String imageFormat)throws Exception{
		File tempImage = ImageIOHelper.createImage(imageFile,imageFormat);
		File outputFile = new File(imageFile.getParentFile(),"output");
		StringBuffer strB = new StringBuffer();
		List<String> cmd = new ArrayList<String>();
		if(OS.isWindowsXP()){
			cmd.add(tessPath+"//tesseract");
		}else if(OS.isLinux()){
			cmd.add("tesseract");
		}else{
			cmd.add(tessPath+"//tesseract");
		}
		cmd.add("");
		cmd.add(outputFile.getName());
		//cmd.add(LANG_OPTION);
		//cmd.add("chi_sim");
		//cmd.add("eng");
		
		ProcessBuilder pb = new ProcessBuilder();
		pb.directory(imageFile.getParentFile());
		
		cmd.set(1, tempImage.getName());
		pb.command(cmd);
		pb.redirectErrorStream(true);
		
		Process process = pb.start();
		//tesseract.exe 1.jpg 1 -l chi_sim
		int w = process.waitFor();
		
		//删除临时正在工作文件
		tempImage.delete();
		
		if(w==0){
			BufferedReader in = new BufferedReader(new InputStreamReader(new FileInputStream(outputFile.getAbsolutePath()+".txt"),"UTF-8"));
			
			String str;
			while((str = in.readLine())!=null){
				strB.append(str).append(EOL);
			}
			in.close();
		}else{
			String msg;
			switch(w){
				case 1:
					msg = "Errors accessing files.There may be spaces in your image's filename.";
					break;
				case 29:
					msg = "Cannot recongnize the image or its selected region.";
					break;
				case 31:
					msg = "Unsupported image format.";
					break;
				default:
					msg = "Errors occurred.";
			}
			tempImage.delete();
			//throw new RuntimeException(msg);
		}
		new File(outputFile.getAbsolutePath()+".txt").delete();
		return strB.toString();
	}
}

c.main

package OCR;
import java.io.File;
import java.io.IOException;

public class TestOcr {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		//输入图片地址
		String path = "d://test//test.bmp";   
        try {   
            String valCode = new OCR().recognizeText(new File(path), "bmp");   
            System.out.println(valCode);   
        } catch (IOException e) {   
            e.printStackTrace();   
        } catch (Exception e) {
			e.printStackTrace();
		}    
	}

}