CODEWITHSUNDEEP
javaopencv
Bahramdun Adil
Bahramdun Adil

Reputation: 6079

How to convert byte array to Mat object in Java

I want to convert byte array to Mat object, but it throws 

java.lang.UnsupportedOperationException: Provided data element number (60181) should be multiple of the Mat channels count (3)
    at org.opencv.core.Mat.put(Mat.java:992)

It is my code:

byte[] bytes = FileUtils.readFileToByteArray(new File("aaa.jpg"));

Mat mat = new Mat(576, 720, CvType.CV_8UC3);
//Imgcodecs.imencode(".jpg", mat, new MatOfByte(bytes));
mat.put(0, 0, bytes);

I tried many ways and also googled a lot, but did not find any solution.

Note: I know Imgcodecs.imread("aaa.jpg"); and 

BufferedImage img = ImageIO.read(new ByteArrayInputStream(byteArray));
Mat mat = new Mat(img.getHeight(), img.getWidth(), CvType.CV_8UC3);
mat.put(0, 0, ((DataBufferByte) img.getRaster().getDataBuffer()).getData());

But I want to directly convert byte array to Mat without any extra process to speed up the process time.

Thanks in advance!

Upvotes: 8

Views: 21151

Answers (4)

WinDerek
WinDerek

Reputation: 93

// OpenCV 3.x
Mat mat = Imgcodecs.imdecode(new MatOfByte(bytes), Imgcodecs.CV_LOAD_IMAGE_UNCHANGED);
// OpenCV 2.x
Mat mat = Highgui.imdecode(new MatOfByte(bytes), Highgui.CV_LOAD_IMAGE_UNCHANGED);

Upvotes: 0

Log Raj Bhatt
Log Raj Bhatt

Reputation: 177

I've tried this kind of solution. 

 static Mat ba2Mat(byte[] ba)throws Exception{
    // String base64String=Base64.getEncoder().encodeToString(ba);


      //  byte[] bytearray = Base64.getDecoder().decode(base64String);
        Mat mat = Imgcodecs.imdecode(new MatOfByte(ba), 
        Imgcodecs.CV_LOAD_IMAGE_UNCHANGED);
    return mat; 

}

Upvotes: -2

Bahramdun Adil
Bahramdun Adil

Reputation: 6079

I solved the problem like this:

byte[] bytes = FileUtils.readFileToByteArray(new File("aaa.jpg"));
Mat mat = Imgcodecs.imdecode(new MatOfByte(bytes), Imgcodecs.CV_LOAD_IMAGE_UNCHANGED);

Now it works well and much faster than *bytes->BufferedImage->Mat*

Upvotes: 31

Gurkan Yesilyurt
Gurkan Yesilyurt

Reputation: 2675

Try it please. I'm using this.

BufferedImage b = ImageIO.read(url);
BufferedImage b1 = new BufferedImage(b.getWidth(), b.getHeight(), BufferedImage.TYPE_3BYTE_BGR);
b1=b;
byte [] pixels = ((DataBufferByte)b1.getRaster().getDataBuffer()).getData();

Mat myPic = new Mat(b1.getHeight(),b1.getWidth(),CvType.CV_8UC3);
myPic.put(0, 0, pixels);

Or

OpenCV imread()

Mat myPic = Highgui.imread(url);

Upvotes: 0

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