Question

大家好我想尝试运行Tesseract并从图像中获取文本但我遇到以下错误：

Exception in thread "main" java.lang.Error: Invalid memory access
at com.sun.jna.Native.invokePointer(Native Method)
at com.sun.jna.Function.invokePointer(Function.java:477)
at com.sun.jna.Function.invoke(Function.java:411)
at com.sun.jna.Function.invoke(Function.java:323)
at com.sun.jna.Library$Handler.invoke(Library.java:236)
at com.sun.proxy.$Proxy0.TessBaseAPIGetUTF8Text(Unknown Source)
at net.sourceforge.tess4j.Tesseract.getOCRText(Tesseract.java:436)
at net.sourceforge.tess4j.Tesseract.doOCR(Tesseract.java:291)
at net.sourceforge.tess4j.Tesseract.doOCR(Tesseract.java:212)
at net.sourceforge.tess4j.Tesseract.doOCR(Tesseract.java:196)
at Crop_Image.main(Crop_Image.java:98)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)
Error opening data file ./tessdata/eng.traineddata
Please make sure the TESSDATA_PREFIX environment variable is set to the parent directory of your "tessdata" directory.
Failed loading language 'eng'
Tesseract couldn't load any languages!

我正在加载包含英文文本的图像文件jpg。这是我尝试加载文件然后尝试从中获取文本的方式：

 public static void main(String[] args){

    String result = "";

    File imageFile = new File("C:\\Users\\user\\Desktop\\Untitled.jpg");
    Tesseract instance = new Tesseract();

    try {
         result = instance.doOCR(imageFile);
         result.toString();

    } catch (Exception e) {
        e.printStackTrace();
        System.err.println(e.getMessage());
    }
}

此外，我也使用Maven在我的项目中，这是我的pom文件：

<dependencies>

    <dependency>
        <groupId>nu.pattern</groupId>
        <artifactId>opencv</artifactId>
        <version>2.4.9-4</version>
    </dependency>

    <dependency>
        <groupId>net.sourceforge.tess4j</groupId>
        <artifactId>tess4j</artifactId>
        <version>3.1.0</version>
    </dependency>

</dependencies>

导致此错误的原因是什么？

Answer 1

我看到了您的代码，初始化Tesseract的方式可能存在问题。现在，因为您使用maven作为nguyenq建议您需要准确指出库的位置 - tessdata所以这是您应该做的：

  public static String Image_To_Text(String image_path){

    String result = "";

    File imageFile = new File("your path to your image");

    Tesseract instance = Tesseract.getInstance();
    //In case you don't have your own tessdata, let it also be extracted for you
    File tessDataFolder = LoadLibs.extractTessResources("tessdata");

    //Set the tessdata path
    instance.setDatapath(tessDataFolder.getAbsolutePath());

    try {
         result = instance.doOCR(imageFile);

    } catch (Exception e) {
        e.printStackTrace();            
    }

    return result;
}

Answer 2

您需要将instance.setDatapath设置为tessdata文件夹的父目录。

File tessDataFolder = LoadLibs.extractTessResources("tessdata"); // Maven build bundles English data
instance.setDatapath(tessDataFolder.getParent());

请参阅http://tess4j.sourceforge.net/tutorial。

Android：Tesseract无法加载任何语言

2 个答案: