识别图片内容报错：

14:42:17.089 [main] ERROR net.sourceforge.tess4j.Tesseract - Error reading PNG metadata
javax.imageio.IIOException: Error reading PNG metadata
    at com.sun.imageio.plugins.png.PNGImageReader.readMetadata(PNGImageReader.java:796)
    at com.sun.imageio.plugins.png.PNGImageReader.readImage(PNGImageReader.java:1256)
    at com.sun.imageio.plugins.png.PNGImageReader.read(PNGImageReader.java:1614)
    at javax.imageio.ImageReader.readAll(ImageReader.java:1066)
    at net.sourceforge.tess4j.Tesseract.doOCR(Tesseract.java:226)
    at net.sourceforge.tess4j.Tesseract.doOCR(Tesseract.java:194)
    at tools.image.ImageUtil.getString(ImageUtil.java:31)
    at tools.image.ImageUtil.main(ImageUtil.java:40)
Caused by: javax.imageio.IIOException: Failed to read a chunk of type 1933723988
    at com.sun.imageio.plugins.png.PNGImageReader.readMetadata(PNGImageReader.java:790)
    ... 7 common frames omitted
javax.imageio.IIOException: Error reading PNG metadata

下面左边是刚开始使用的图片，图片是自己裁剪过的，识别的时候报了上面的错，查看图片发现图片上的字很模糊，怀疑是这个导致的报错，后来把图片转换为灰度图像，再识别就可以了