<html>
<head>
<title>等比例缩放图片--www.jb200.com</title>
<script>
function drawimage(imgd,iwidth,iheight){
//参数(图片,允许的宽度,允许的高度)
var image=new image();
image.src=imgd.src;
if(image.width>0 && image.height>0){
if(image.width/image.height>= iwidth/iheight){
if(image.width>iwidth){
imgd.width=iwidth;
imgd.height=(image.height*iwidth)/image.width;
}else{
imgd.width=image.width;
imgd.height=image.height;
}
}else{
if(image.height>iheight){
imgd.height=iheight;
imgd.width=(image.width*iheight)/image.height;
}else{
imgd.width=image.width;
imgd.height=image.height;
}
}
}
}
</script>
</head>
<body>
<img src="/images/logo.gif" alt="自动缩放后的效果" width="220" height="80" onload="javascript:drawimage(this,100,100)" />
</body>
</html>
