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// Let me show approch without JQuery. Simple JS function:

function isVisible(elem) {
	var coords = elem.getBoundingClientRect();
	var topVisible = coords.top > 0 && coords.top < 0;
	var bottomVisible = coords.bottom < shift && coords.bottom > 0;
	return topVisible || bottomVisible;
}

// Short example how to use it:

var img = document.getElementById("pic1");
if (isVisible(img)) { img.style.opacity = "1.00";  }