Rotated image is not centralized in opencv4android

[Khawar khan]

Hi, I've successfully rotated image in opencv (4android), using code below

 // -----CALCULATION FOR NEW WIDTH/HEIGHT------

double radians = Math.toRadians(Angle);

double sin = Math.abs(Math.sin(radians));

double cos = Math.abs(Math.cos(radians));

   

double radian = Math.toRadians(waterMarkAngle);

int newWidth = (int) (scaledImage.width() * cos + scaledImage.height() * sin);

int newHeight = (int) (scaledImage.width() * sin + scaledImage.height() * cos);

// rotating water image

org.opencv.core.Point center = new org.opencv.core.Point(newWidth/2, newHeight/2);

Mat rotImage = Imgproc.getRotationMatrix2D(center, waterMarkAngle, 1.0); // 1.0 means 100 % scale

Size s = new Size(newWidth, newHeight);

Imgproc.warpAffine(scaledImage, scaledImage, rotImage, s,Imgproc.INTER_LINEAR + Imgproc.CV_WARP_FILL_OUTLIERS);//

Highgui.imwrite("mnt/sdcard/rotatedWatermark.png",scaledImage);

// result http://www.freeimagehosting.net/hb51q

how do I centralize this resultant image?

Thanks in advance.

[Alexander Smorkalov]

What do you mean in word "centralize"?
If you want to get rectangle image without black borders you need to get submat with your region of interest.

[Khawar khan]

Thanks for your help.. what I'm doing is that I've rotated an image so its edges were cut off, then I used a formula to get new width/height of an image after rotation, so how do I make it translate to center of the new sized rectange.. this is what I'm doing.. If you have any good solution please do share..