无法在特定图片上施放Databufferint到Databufferbyte
我正在尝试提高图像的阈值，但是其中一些人在铸造到Databufferbyte时有问题。我在这里发布了两种类型的图片 - 第一张图片（test1.jpg很好，可以铸造到databufferbyte），第二个图片（test2.jpg抛出例外）。
图像：
这是我的代码：
public static void main(String[] args) throws IOException {
System.loadLibrary( Core.NATIVE_LIBRARY_NAME );
BufferedImage bufferedImage = ImageIO.read(new File("/test/test2.jpg"));
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
ImageIO.write(bufferedImage, "jpg", byteArrayOutputStream);
byte[] input = byteArrayOutputStream.toByteArray();
InputStream is = new ByteArrayInputStream(input);
bufferedImage = ImageIO.read(is);
byte[] data = ((DataBufferByte) bufferedImage.getRaster().getDataBuffer()).getData();
Mat mat = new Mat(bufferedImage.getHeight(), bufferedImage.getWidth(), CvType.CV_8UC3);
mat.put(0, 0, data);
Mat mat1 = new Mat(bufferedImage.getHeight(),bufferedImage.getWidth(),CvType.CV_8UC1);
Imgproc.cvtColor(mat, mat1, Imgproc.COLOR_RGB2GRAY);
byte[] data1 = new byte[mat1.rows() * mat1.cols() * (int)(mat1.elemSize())];
mat1.get(0, 0, data1);
Mat dst = new Mat();
Imgproc.adaptiveThreshold(mat1, dst, 255, Imgproc.ADAPTIVE_THRESH_MEAN_C, Imgproc.THRESH_BINARY, 11, 15);
MatOfByte matOfByte = new MatOfByte();
Imgcodecs.imencode(".jpg", dst, matOfByte);
ByteArrayInputStream inputStream = new ByteArrayInputStream(matOfByte.toArray());
bufferedImage = ImageIO.read(inputStream);
ImageIO.write(bufferedImage, "jpg", new File("/test_output/test2.jpg"));
}
test1.jpg映像的输出正确：
”
线程“ main” java.lang.classcastException中的例外： java.awt.image.databufferint不能施放 java.awt.image.databufferbyte
在线
byte[] data = ((DataBufferByte) bufferedImage.getRaster().getDataBuffer()).getData();
有什么问题？为什么将.jpg图像转换而毫无问题，但第二次抛出了例外？
I am trying to threshold my images, but some of them have problem with casting to DataBufferByte. I post here two types of pictures - the first (the test1.jpg is good and can be casted to DataBufferByte), the second (test2.jpg throwing an exception).
Images:
Here is my code:
public static void main(String[] args) throws IOException {
System.loadLibrary( Core.NATIVE_LIBRARY_NAME );
BufferedImage bufferedImage = ImageIO.read(new File("/test/test2.jpg"));
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
ImageIO.write(bufferedImage, "jpg", byteArrayOutputStream);
byte[] input = byteArrayOutputStream.toByteArray();
InputStream is = new ByteArrayInputStream(input);
bufferedImage = ImageIO.read(is);
byte[] data = ((DataBufferByte) bufferedImage.getRaster().getDataBuffer()).getData();
Mat mat = new Mat(bufferedImage.getHeight(), bufferedImage.getWidth(), CvType.CV_8UC3);
mat.put(0, 0, data);
Mat mat1 = new Mat(bufferedImage.getHeight(),bufferedImage.getWidth(),CvType.CV_8UC1);
Imgproc.cvtColor(mat, mat1, Imgproc.COLOR_RGB2GRAY);
byte[] data1 = new byte[mat1.rows() * mat1.cols() * (int)(mat1.elemSize())];
mat1.get(0, 0, data1);
Mat dst = new Mat();
Imgproc.adaptiveThreshold(mat1, dst, 255, Imgproc.ADAPTIVE_THRESH_MEAN_C, Imgproc.THRESH_BINARY, 11, 15);
MatOfByte matOfByte = new MatOfByte();
Imgcodecs.imencode(".jpg", dst, matOfByte);
ByteArrayInputStream inputStream = new ByteArrayInputStream(matOfByte.toArray());
bufferedImage = ImageIO.read(inputStream);
ImageIO.write(bufferedImage, "jpg", new File("/test_output/test2.jpg"));
}
The output for test1.jpg image is correct:
But the second image throwing an exception
Exception in thread "main" java.lang.ClassCastException:
java.awt.image.DataBufferInt cannot be cast to
java.awt.image.DataBufferByte
at line
byte[] data = ((DataBufferByte) bufferedImage.getRaster().getDataBuffer()).getData();
What is the problem ? Why the one .jpg image is converted without problems but second throwing an exception?
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两者都不具有相同的格式。一个使用8位用于颜色表示和其他3x8位（SO 4个字节，带有填充或透明度）？
查看它给出：
image1：JPEG图像数据，JFIF标准1.01，纵横比，密度1x1，段长度16，基线，Precision 8，449x361，组件3
image2：PNG图像数据，617 x 353，8位/彩色RGBA，非颜色RGBA，非 - 间隔
您可以在缓冲区上使用
getDatatype（）方法来获取颜色表示的大小。Both are not of the same format. One using 8-bit for color representation and the other 3x8-bit (so 4 bytes, with padding or transparency)?
Looking at it give:
image1 : JPEG image data, JFIF standard 1.01, aspect ratio, density 1x1, segment length 16, baseline, precision 8, 449x361, components 3
image2 : PNG image data, 617 x 353, 8-bit/color RGBA, non-interlaced
You may use the
getDataType()method on the buffer to get the size of the color representation.