Bibliography

[1] Thomas Porter and Tom Duff, “Composing Digital Images,” Computer Graphics Volume 18, Number 3 July 1984 pp 253-259, 1984. http://keithp.com/~keithp/porterduff/

 
var _hmt = _hmt || []; (function() { var hm = document.createElement("script"); hm.src = "https://hm.baidu.com/hm.js?f1ba5b4a33d29d84db69f029b9ace483"; var s = document.getElementsByTagName("script")[0]; s.parentNode.insertBefore(hm, s); })();