<script type="text/javascript"> 
var setNewsImg = function(obj){ 
$(obj).find('img').each(function(i){ 
var imgw = $(this).width(); 
var imgh = $(this).height(); 
var scale=1; 
if(imgw>634){ 
scale = 634/imgw; 
console.log(scale); 
$(this).height(scale*imgh); 
$(this).width(scale*imgw); 
} 
}); 
} 
</script type="text/javascripy"> 
调用 
<script> 
$(function(){ 
setNewsImg('.news-img') 
}) 
</script> 

$(window).bind("load", function() { 
 // 图片修改大小 
 $('#imglist img').each(function() { 
  var maxWidth = 120; //初始化最大显示宽度
  var maxHeight = 120; //初始化最大显示高度
  var ratio = 0; 
  var width = $(this).width(); 
  var height = $(this).height(); 
  
  if(width > maxWidth){ 
   ratio = maxWidth / width; 
   $(this).css("width", maxWidth); 
   $(this).css("height", height * ratio); 
   height = height * ratio; 
  } 
  
  if(height > maxHeight){ 
   ratio = maxHeight / height; 
   $(this).css("height", maxHeight); 
   $(this).css("width", width * ratio); 
   width = width * ratio; 
  } 
 }); 
});

<script>
$(function(){
$(".daima img").each(function(){
maxWidth =700;
ratio = 0;
width = $(this).width();
height = $(this).height();
if(width > maxWidth){
ratio = maxWidth / width;
$(this).width(maxWidth);
height = height * ratio;
$(this).height(parseInt(height));
}});
});
</script>

$('#content').find('img').each(function(){
    var img = this;
    if (img.width > 600) {
      img.style.width = "600px";
      img.style.height = "auto";
      //$(img).removeAttr('height');
      var aTag = document.createElement('a');
      aTag.href = img.src;
   aTag.target="_blank";
      $(aTag).addClass('bPic')
      .insertAfter(img).append(img)
      .lightBox(options);
    }
  });