How to load BufferedImage into opencv_core.Mat?

[Darrel Riekhof]

Using latest bytedeco stuff with opencv 2.4.9

I'm trying to do this:

BufferedImage bi = VeraImgUtils.matToBufferedImage(matFace, null);

try {

bi = ImageIO.read(new File("C:/dev/workspace-kgicv/JavaCV-samples/src/Rice.jpg"));

} catch (IOException e) {

e.printStackTrace();

}

JOptionPane.showMessageDialog(null, "", "face bi", JOptionPane.INFORMATION_MESSAGE,

new ImageIcon(bi));

mm.copyFrom(bi);  // line 190

BufferedImage is loaded and shows up in the JOptionPane.

I'm getting this stacktrace:

Exception in thread "Thread-4" java.lang.NullPointerException

at org.bytedeco.javacpp.helper.opencv_core$AbstractArray.getByteBuffer(opencv_core.java:164)

at org.bytedeco.javacpp.helper.opencv_core$AbstractArray.copyFrom(opencv_core.java:599)

at org.bytedeco.javacpp.helper.opencv_core$AbstractArray.copyFrom(opencv_core.java:594)

at org.bytedeco.javacpp.helper.opencv_core$AbstractArray.copyFrom(opencv_core.java:586)

at org.bytedeco.javacpp.helper.opencv_core$AbstractArray.copyFrom(opencv_core.java:583)

at com.foo.face.FaceClassifier.detect(FaceClassifier.java:190)

        ...

at java.lang.Thread.run(Thread.java:745)

[Darrel Riekhof]

Well, I guess nevermind.  Looks like it works if I give the opencv_core.Mat constructor the width, height, and type:

    opencv_core.Mat mm = new opencv_core.Mat(matFace.rows(), matFace.cols(), matFace.type());

It would be nice if I didn't need to provide those--pretty sure the OpenCV java bindings don't require that when using copyTo().  But not a big deal.

[Samuel Audet]

On 05/03/2014 01:07 AM, Darrel Riekhof wrote:
> Well, I guess nevermind. Looks like it works if I give the opencv_core.Mat constructor the width, height, and type:
>
> opencv_core.Mat mm = new opencv_core.Mat(matFace.rows(), matFace.cols(), matFace.type());
>
> It would be nice if I didn't need to provide those--pretty sure the OpenCV java bindings don't require that when using copyTo(). But not a big deal.

There's Mat.createFrom() that should do what you need:
https://github.com/bytedeco/javacpp-presets/blob/master/opencv/src/main/java/org/bytedeco/javacpp/helper/opencv_core.java#L2300
But whoops, I forgot to put them static. I'll be fixing that.

If possible, please open an issue here (just copy/paste), thanks!
https://github.com/bytedeco/javacpp-presets/issues

Samuel

[Samuel Audet]

Issue and fix reported here:
https://github.com/bytedeco/javacpp-presets/issues/1
Thanks for your input!

Samuel