Opencv android, capture image

Question

I will try to simplify my problem. Lets say i just want to see grayscale images using camera, i do it this way:

public Mat onCameraFrame(CvCameraViewFrame inputF         


        

Answer 1

It is because you are modifying Mat in onCameraFrame() and writing the image data to file in onPictureTaken().

The Mat in onCameraFrame is never written to the file.

The byte[] in onPictureTaken() contains the picture taken by the camera when you push a button or touch on the screen whatever is triggering takePicture().

If you want to the write picture with some effects then you will have to convert byte[] to Mat and then make effects in this Mat and then write it to file using imwrite() or convert the modified Mat back to byte[] and then write it to file using FileOutputStream as shown in your code.

imwrite() will be slower than the FileOutputStream approach

Answer 2

This is super duper old but I saw it so many times while searching. I solved my issue by using

Imgcodecs.imwrite(fileName,mRgba);

instead of

javaCameraView.takePicture(fileName);

in my onTouch method.