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java零碎要点—Tesseract 3.0,Java OCR 图像智能字符识别技术,可识别中文

2019年09月16日 ⁄ 综合 ⁄ 共 14447字 ⁄ 字号 评论关闭

2.Java OCR 图像智能字符识别技术,可识别中文 
几天一直在研究OCR技术,据我了解的情况,国内最专业的OCR软件只有2家,清华TH-OCR和汉王OCR,看了很多的OCR

技术发现好多对英文与数字的支持都很好,可惜很多都不支持中文字符。Asprise-OCR,Tesseract 3.0以前的版本

,都不支持中文,其实我用了下Asprise-OCR算是速度比较的快了,可惜他鄙视中文,这个没有办法,正好这段时间

知名的开源OCR引擎Tesseract 3.0版本发布了,他给我们带来的好消息就是支持中文,相关的下载项目网站是:

http://code.google.com/p/tesseract-ocr

 
虽然速度不是很客观可是毕竟人家开始支持中文也算是不错的,一个英文的语言包大概是1.8M,中文简体的语言包是

39.5M,中文繁体的语言包是53M,这样就知道为什么识别中文慢的原因了
----------------------------------------------------------------------
利用开源程序(ImageMagick+tesseract-ocr)实现图像验证码识别 
 
  但却很少看到在windows下的相关文章介绍。
 
  接下来我将一步步讲述如何采用tesseract-ocr识别含有中文的图片。
 
1、下载tesseract-ocr(注意3.0版本之后才支持中文的识别)
 
      tesseract-ocr-setup-3.00.exe      

      chi_sim.traineddata.gz   
 
2、安装tesseract-ocr
 
      解压缩,双击 tesseract-ocr-setup-3.00.exe 即可根据提示一步步安装,本人安装的目录是:D:/Program 

Files/Tesseract-OCR
 
      在该目录下可看到tesseract.exe文件,这就是我们后面程序中会调用到的运行进程。
 
3、自定义安装语言包
 
      D:/Program Files/Tesseract-OCR目录下找到/tessdata目录,其是用来存放语言包,可把 

chi_sim.traineddata.gz   解压缩之后的chi_sim.traineddata文件复制到该目录下即可。
 
4、编写测试代码
 
        在编写代码之前下载两个jar包:jai_imageio-1.1-alpha.jar、swingx-1.0.jar,可在www.findjar.com 

网站上去下载。
----------------------------------------------------------------------------------
 下面是自己测试用的所有代码:
---------------------------------
1.新建项目:javaocr2
-------------------------
/javaocr2/src/com/credream/ocr/ImageFilter.java
package com.credream.ocr;

import java.awt.Graphics2D;
import java.awt.color.ColorSpace;
import java.awt.geom.AffineTransform;
import java.awt.image.AffineTransformOp;
import java.awt.image.BufferedImage;
import java.awt.image.ColorConvertOp;
import java.awt.image.ColorModel;
import java.awt.image.MemoryImageSource;
import java.awt.image.PixelGrabber;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 
 * 图像过滤,增强OCR识别成功率
 * 
 */
public class ImageFilter {
protected transient final Logger logger = LoggerFactory.getLogger(this.getClass());
private BufferedImage image;

private int iw, ih;

private int[] pixels;

public ImageFilter(BufferedImage image) {
this.image = image;
iw = image.getWidth();
ih = image.getHeight();
pixels = new int[iw * ih];
}

/** 图像二值化 */
public BufferedImage changeGrey() {
PixelGrabber pg = new PixelGrabber(image.getSource(), 0, 0, iw, ih, pixels, 0, iw);
try {
pg.grabPixels();
} catch (InterruptedException e) {
logger.error("异常:", e);
}
// 设定二值化的域值,默认值为100
int grey = 100;
// 对图像进行二值化处理,Alpha值保持不变
ColorModel cm = ColorModel.getRGBdefault();
for (int i = 0; i < iw * ih; i++) {
int red, green, blue;
int alpha = cm.getAlpha(pixels[i]);
if (cm.getRed(pixels[i]) > grey) {
red = 255;
} else {
red = 0;
}

if (cm.getGreen(pixels[i]) > grey) {
green = 255;
} else {
green = 0;
}

if (cm.getBlue(pixels[i]) > grey) {
blue = 255;
} else {
blue = 0;
}

pixels[i] = alpha << 24 | red << 16 | green << 8 | blue;
}
// 将数组中的象素产生一个图像
return ImageIOHelper.imageProducerToBufferedImage(new MemoryImageSource(iw, ih, 

pixels, 0, iw));
}

/** 提升清晰度,进行锐化 */
public BufferedImage sharp() {
PixelGrabber pg = new PixelGrabber(image.getSource(), 0, 0, iw, ih, pixels, 0, iw);
try {
pg.grabPixels();
} catch (InterruptedException e) {
logger.error("异常:", e);
}

// 象素的中间变量
int tempPixels[] = new int[iw * ih];
for (int i = 0; i < iw * ih; i++) {
tempPixels[i] = pixels[i];
}
// 对图像进行尖锐化处理,Alpha值保持不变
ColorModel cm = ColorModel.getRGBdefault();
for (int i = 1; i < ih - 1; i++) {
for (int j = 1; j < iw - 1; j++) {
int alpha = cm.getAlpha(pixels[i * iw + j]);

// 对图像进行尖锐化
int red6 = cm.getRed(pixels[i * iw + j + 1]);
int red5 = cm.getRed(pixels[i * iw + j]);
int red8 = cm.getRed(pixels[(i + 1) * iw + j]);
int sharpRed = Math.abs(red6 - red5) + Math.abs(red8 - red5);

int green5 = cm.getGreen(pixels[i * iw + j]);
int green6 = cm.getGreen(pixels[i * iw + j + 1]);
int green8 = cm.getGreen(pixels[(i + 1) * iw + j]);
int sharpGreen = Math.abs(green6 - green5) + Math.abs(green8 - 

green5);

int blue5 = cm.getBlue(pixels[i * iw + j]);
int blue6 = cm.getBlue(pixels[i * iw + j + 1]);
int blue8 = cm.getBlue(pixels[(i + 1) * iw + j]);
int sharpBlue = Math.abs(blue6 - blue5) + Math.abs(blue8 - blue5);

if (sharpRed > 255) {
sharpRed = 255;
}
if (sharpGreen > 255) {
sharpGreen = 255;
}
if (sharpBlue > 255) {
sharpBlue = 255;
}

tempPixels[i * iw + j] = alpha << 24 | sharpRed << 16 | sharpGreen << 

8 | sharpBlue;
}
}

// 将数组中的象素产生一个图像
return ImageIOHelper.imageProducerToBufferedImage(new MemoryImageSource(iw, ih, 

tempPixels, 0, iw));
}

/** 中值滤波 */
public BufferedImage median() {
PixelGrabber pg = new PixelGrabber(image.getSource(), 0, 0, iw, ih, pixels, 0, iw);
try {
pg.grabPixels();
} catch (InterruptedException e) {
logger.error("异常:", e);
}
// 对图像进行中值滤波,Alpha值保持不变
ColorModel cm = ColorModel.getRGBdefault();
for (int i = 1; i < ih - 1; i++) {
for (int j = 1; j < iw - 1; j++) {
int red, green, blue;
int alpha = cm.getAlpha(pixels[i * iw + j]);

// int red2 = cm.getRed(pixels[(i - 1) * iw + j]);
int red4 = cm.getRed(pixels[i * iw + j - 1]);
int red5 = cm.getRed(pixels[i * iw + j]);
int red6 = cm.getRed(pixels[i * iw + j + 1]);
// int red8 = cm.getRed(pixels[(i + 1) * iw + j]);

// 水平方向进行中值滤波
if (red4 >= red5) {
if (red5 >= red6) {
red = red5;
} else {
if (red4 >= red6) {
red = red6;
} else {
red = red4;
}
}
} else {
if (red4 > red6) {
red = red4;
} else {
if (red5 > red6) {
red = red6;
} else {
red = red5;
}
}
}

// int green2 = cm.getGreen(pixels[(i - 1) * iw + j]);
int green4 = cm.getGreen(pixels[i * iw + j - 1]);
int green5 = cm.getGreen(pixels[i * iw + j]);
int green6 = cm.getGreen(pixels[i * iw + j + 1]);
// int green8 = cm.getGreen(pixels[(i + 1) * iw + j]);

// 水平方向进行中值滤波
if (green4 >= green5) {
if (green5 >= green6) {
green = green5;
} else {
if (green4 >= green6) {
green = green6;
} else {
green = green4;
}
}
} else {
if (green4 > green6) {
green = green4;
} else {
if (green5 > green6) {
green = green6;
} else {
green = green5;
}
}
}

// int blue2 = cm.getBlue(pixels[(i - 1) * iw + j]);
int blue4 = cm.getBlue(pixels[i * iw + j - 1]);
int blue5 = cm.getBlue(pixels[i * iw + j]);
int blue6 = cm.getBlue(pixels[i * iw + j + 1]);
// int blue8 = cm.getBlue(pixels[(i + 1) * iw + j]);

// 水平方向进行中值滤波
if (blue4 >= blue5) {
if (blue5 >= blue6) {
blue = blue5;
} else {
if (blue4 >= blue6) {
blue = blue6;
} else {
blue = blue4;
}
}
} else {
if (blue4 > blue6) {
blue = blue4;
} else {
if (blue5 > blue6) {
blue = blue6;
} else {
blue = blue5;
}
}
}
pixels[i * iw + j] = alpha << 24 | red << 16 | green << 8 | blue;
}
}

// 将数组中的象素产生一个图像
return ImageIOHelper.imageProducerToBufferedImage(new MemoryImageSource(iw, ih, 

pixels, 0, iw));
}

/** 线性灰度变换 */
public BufferedImage lineGrey() {
PixelGrabber pg = new PixelGrabber(image.getSource(), 0, 0, iw, ih, pixels, 0, iw);
try {
pg.grabPixels();
} catch (InterruptedException e) {
logger.error("异常:", e);
}
// 对图像进行进行线性拉伸,Alpha值保持不变
ColorModel cm = ColorModel.getRGBdefault();
for (int i = 0; i < iw * ih; i++) {
int alpha = cm.getAlpha(pixels[i]);
int red = cm.getRed(pixels[i]);
int green = cm.getGreen(pixels[i]);
int blue = cm.getBlue(pixels[i]);

// 增加了图像的亮度
red = (int) (1.1 * red + 30);
green = (int) (1.1 * green + 30);
blue = (int) (1.1 * blue + 30);
if (red >= 255) {
red = 255;
}
if (green >= 255) {
green = 255;
}
if (blue >= 255) {
blue = 255;
}
pixels[i] = alpha << 24 | red << 16 | green << 8 | blue;
}

// 将数组中的象素产生一个图像

return ImageIOHelper.imageProducerToBufferedImage(new MemoryImageSource(iw, ih, 

pixels, 0, iw));
}

/** 转换为黑白灰度图 */
public BufferedImage grayFilter() {
ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_GRAY);
ColorConvertOp op = new ColorConvertOp(cs, null);
return op.filter(image, null);
}

/** 平滑缩放 */
public BufferedImage scaling(double s) {
AffineTransform tx = new AffineTransform();
tx.scale(s, s);
AffineTransformOp op = new AffineTransformOp(tx, AffineTransformOp.TYPE_BILINEAR);
return op.filter(image, null);
}

public BufferedImage scale(Float s) {
int srcW = image.getWidth();
int srcH = image.getHeight();
int newW = Math.round(srcW * s);
int newH = Math.round(srcH * s);
// 先做水平方向上的伸缩变换
BufferedImage tmp=new BufferedImage(newW, newH, image.getType()); 
Graphics2D g= tmp.createGraphics(); 
for (int x = 0; x < newW; x++) {
g.setClip(x, 0, 1, srcH);
// 按比例放缩
g.drawImage(image, x - x * srcW / newW, 0, null);
}

// 再做垂直方向上的伸缩变换
BufferedImage dst = new BufferedImage(newW, newH, image.getType()); 
g = dst.createGraphics();
for (int y = 0; y < newH; y++) {
g.setClip(0, y, newW, 1);
// 按比例放缩
g.drawImage(tmp, 0, y - y * srcH / newH, null);
}
return dst;
}

}
----------------------------------------------------------
2./javaocr2/src/com/credream/ocr/ImageIOHelper.java
/*
 * ImageIOHelper.java
 *
 * Created on December 24, 2007, 1:15 AM
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */

package com.credream.ocr;

import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferByte;
import java.awt.image.ImageProducer;
import java.awt.image.WritableRaster;
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 javax.swing.JOptionPane;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

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

public class ImageIOHelper {
protected transient final static Logger logger = LoggerFactory.getLogger

(ImageIOHelper.class);
public ImageIOHelper() {
}

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.US);
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 (Exception exc) {
logger.error("异常:", exc);
}
return tempFile;
}

public static File createImage(BufferedImage bi) {
File tempFile = null;
try {
tempFile = File.createTempFile("tempImageFile", ".tif");
tempFile.deleteOnExit();
TIFFImageWriteParam tiffWriteParam = new TIFFImageWriteParam(Locale.US);
tiffWriteParam.setCompressionMode(ImageWriteParam.MODE_DISABLED);

// Get tif writer and set output to file
Iterator<ImageWriter> writers = ImageIO.getImageWritersByFormatName("tiff");
ImageWriter writer = writers.next();

IIOImage image = new IIOImage(bi, null, null);
tempFile = tempImageFile(tempFile);
ImageOutputStream ios = ImageIO.createImageOutputStream(tempFile);
writer.setOutput(ios);
writer.write(null, image, tiffWriteParam);
ios.close();
writer.dispose();
} catch (Exception exc) {
logger.error("异常:", exc);
}
return tempFile;
}

public 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"));
}

public static BufferedImage getImage(File imageFile) {
BufferedImage al = null;
try {
String imageFileName = imageFile.getName();
String imageFormat = imageFileName.substring(imageFileName.lastIndexOf('.') + 

1);
Iterator<ImageReader> readers = ImageIO.getImageReadersByFormatName

(imageFormat);
ImageReader reader = readers.next();

if (reader == null) {
JOptionPane.showConfirmDialog(null,
"Need to install JAI Image I/O package.

\nhttps://jai-imageio.dev.java.net");
return null;
}

ImageInputStream iis = ImageIO.createImageInputStream(imageFile);
reader.setInput(iis);

al = reader.read(0);

reader.dispose();
} catch (IOException ioe) {
System.err.println(ioe.getMessage());
} catch (Exception e) {
System.err.println(e.getMessage());
}

return al;
}

public static BufferedImage imageToBufferedImage(Image image) {
BufferedImage bufferedImage = new BufferedImage(image.getWidth(null), 

image.getHeight(null),
BufferedImage.TYPE_INT_RGB);
Graphics2D g = bufferedImage.createGraphics();
g.drawImage(image, 0, 0, null);
return bufferedImage;
}

public static BufferedImage imageProducerToBufferedImage(ImageProducer imageProducer) {
return imageToBufferedImage(Toolkit.getDefaultToolkit().createImage(imageProducer));
}

public static byte[] image_byte_data(BufferedImage image) {
WritableRaster raster = image.getRaster();
DataBufferByte buffer = (DataBufferByte) raster.getDataBuffer();
return buffer.getData();
}
}

-----------------------------------------------------------
4./javaocr2/src/com/credream/ocr/OCR.java
/*
 * OCR.java
 *
 * Created on December 24, 2007, 12:38 AM
 */

package com.credream.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;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class OCR {
protected transient final Logger logger = LoggerFactory.getLogger(this.getClass());
private final String LANG_OPTION = "-l";
private final String EOL = System.getProperty("line.separator");
private String tessPath ="D://Program Files//Tesseract-OCR"; 
//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("eng");

ProcessBuilder pb = new ProcessBuilder();
pb.directory(imageFile.getParentFile());

cmd.set(1, tempImage.getName());
pb.command(cmd);
pb.redirectErrorStream(true);
Process process = pb.start();

int w = process.waitFor();
logger.debug("Exit value = {}", w);

// delete temp working files
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 recognize 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();
logger.info("图像识别结果:{}", strB);
return strB.toString();
}
}
------------------------------------------------------------------------------------
5./javaocr2/src/com/credream/ocr/TestOCR.java
package com.credream.ocr;

import java.io.File;
import java.io.IOException;

public class TestOCR {
 public static void main(String[] args) {   
       String path = "D://test//mytest.jpg";      
       System.out.println("ORC Test Begin......");
       try {      
           String valCode = new OCR().recognizeText(new File(path), "jpg");     
            System.out.println(valCode);      
     //
       } catch (IOException e) {      
           e.printStackTrace();      
       } catch (Exception e) {   
           e.printStackTrace();   
       }        
       System.out.println("ORC Test End......");
   }   
}
----------------------------------------------------------------------
添加了以下jar包:
commons-logging.jar

jai_imageio-1.1-alpha.jar

slf4j-migrator-1.5.2.jar

slf4j-nop-1.5.2.jar

swingx-1.0.jar
-----------------------------------

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