javascriptは画像などのスケールを制御します.

<SCRIPT language="JavaScript">

function DrawImage(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;  

            }  

        }  

    }  

}  



</script>