CSS brightness filter
A simple example of using a CSS brightness filter.
<!DOCTYPE html>
<html>
<head>
<style>
#testImage {
-webkit-filter: brightness(250%);
}
</style>
</head>
<body>
<img id='testImage' style="display:block" src="data:image/gif;base64,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"/>
</body>
</html>