javascript实现获取图片大小及图片等比缩放的方法

var originImage = new Image();
function GetImageWidth(oImage) {
 if (originImage.src != oImage.src) originImage.src = oImage.src;
 return originImage.width;
}
function GetImageHeight(oImage) {
 if (originImage.src != oImage.src) originImage.src = oImage.src;
 return originImage.height;
}

function SetImage(ImgD, FitWidth, FitHeight) {
 var image = new Image();
 image.src = ImgD.src;
 if (image.width > 0 && image.height > 0) {
 if (image.width / image.height >= FitWidth / FitHeight) {
 if (image.width > FitWidth) {
 ImgD.width = FitWidth;
 ImgD.height = (image.height * FitWidth) / image.width;
 } else {
 ImgD.width = image.width;
 ImgD.height = image.height;
 }
 } else {
 if (image.height > FitHeight) {
 ImgD.height = FitHeight;
 ImgD.width = (image.width * FitHeight) / image.height;
 } else {
 ImgD.width = image.width;
 ImgD.height = image.height;
 }
 }
 }
}