Tự code rồi chạy thử... Chạy Thử

<!DOCTYPE html>
<html>
<head>
<title>Chạy thử Css filter contrast</title>
<style>
* { -webkit-box-sizing: border-box; -moz-box-sizing: border-box; box-sizing: border-box;}
img{width:100px;height:auto;}
</style>
</head>
<body>

<h1>Chạy thử Css filter contrast</h1>

<h2>Hình gốc filter: contrast(100%);</h2>
<img style="filter: contrast(100%);" src="https://webmoi.vn/media/images/background-image-full-man-hinh.jpg">

<h2>Hình sáng filter: contrast(150%);</h2>
<img style="filter: contrast(150%);" src="https://webmoi.vn/media/images/background-image-full-man-hinh.jpg">

<h2>Hình filter: contrast(50%);</h2>
<img style="filter: contrast(50%);" src="https://webmoi.vn/media/images/background-image-full-man-hinh.jpg">

<h2>Hình gốc filter: contrast(1);</h2>
<img style="filter: contrast(1);" src="https://webmoi.vn/media/images/background-image-full-man-hinh.jpg">

<h2>Hình sáng filter: contrast(1.6);</h2>
<img style="filter: contrast(1.6);" src="https://webmoi.vn/media/images/background-image-full-man-hinh.jpg">

<h2>Đưa về màu xám filter: contrast(0);</h2>
<img style="filter: contrast(0);" src="https://webmoi.vn/media/images/background-image-full-man-hinh.jpg">

</body>
</html>

Chạy thử Css filter contrast nằm trong bài viết Thuộc tính filter trong CSS