CODE EXAMPLE FOR JAVA

detect view in scrollview android

// consider that your ScrollView is scrollView 
Rect scrollBounds = new Rect();
scrollView.getHitRect(scrollBounds);
if (imageView.getLocalVisibleRect(scrollBounds)) {
    // Any portion of the imageView, even a single pixel, 
    //is within the visible window
} else {
    // NONE of the imageView is within the visible window
}