If you try to get the float type by dividing it, you get 1.0.

contentImage.setOnDoubleTapListener(newGestureDetector.OnDoubleTapListener(){
@ Override
public boolean onSingleTapConfirmed (MotionEvent) {
    return true;
}

@ Override
public boolean onDoubleTap (MotionEvent) {
    int width=contentImage.getDrawable().getIntrinsicWidth();
    intheight=contentImage.getDrawable().getIntrinsicHeight();
    System.out.println("width" + width);
    System.out.println("height" + height);
    int max = Math.max (width, height);
    int min = Math.min (width, height);
    float zoom=max/min;
    System.out.println(zoom);
    contentImage.setZoom(max/min);
    return false;
}

@ Override
public boolean onDoubleTapEvent (MotionEvent) {
    return true;
}});