[javascript] Change image size with JavaScript

I'm trying to change the size of an image with JavaScript. The jS file is separate from the HTML page.

I want to set the height and width of an image in the JS file. Any good ways on doing this?

You can do this:

• .html file:

<img src="src/to/your/img.jpg" id="yourImgId"/>

• .js file:

document.getElementById("yourImgId").style.height = "heightpx";

The same you can do with the width.

you can see the result here In these simple block of code you can change the size of your image ,and make it bigger when the mouse enter over the image , and it will return to its original size when mouve leave.

html:

<div>
<img  onmouseover="fifo()" onmouseleave="fifo()" src="your_image"   
       width="10%"  id="f" >
</div>

js file:

var b=0;
function fifo() {
       if(b==0){
            document.getElementById("f").width = "300";
           b=1;
          }
       else
          {
         document.getElementById("f").width = "100";
          b=0;
        }
   }

You can change the actual width/height attributes like this:

var theImg = document.getElementById('theImgId');
theImg.height = 150;
theImg.width = 150;

If you want to resize an image after it is loaded, you can attach to the onload event of the <img> tag. Note that it may not be supported in all browsers (Microsoft's reference claims it is part of the HTML 4.0 spec, but the HTML 4.0 spec doesn't list the onload event for <img>).

The code below is tested and working in: IE 6, 7 & 8, Firefox 2, 3 & 3.5, Opera 9 & 10, Safari 3 & 4 and Google Chrome:

<img src="yourImage.jpg" border="0" height="real_height" width="real_width"
    onload="resizeImg(this, 200, 100);">

<script type="text/javascript">
function resizeImg(img, height, width) {
    img.height = height;
    img.width = width;
}
</script>

//  This one has print statement so you can see the result at every stage if     you would like.  They are not needed

function crop(image, width, height)
{
    image.width = width;
    image.height = height;
    //print ("in function", image, image.getWidth(), image.getHeight());
    return image;
}

var image = new SimpleImage("name of your image here");
//print ("original", image, image.getWidth(), image.getHeight());
//crop(image,200,300);
print ("final", image, image.getWidth(), image.getHeight());

Changing an image is easy, but how do you change it back to the original size after it has been changed? You may try this to change all images in a document back to the original size:

var i,L=document.images.length;
for(i=0;i<L;++i){
 document.images[i].style.height = 'auto'; //setting CSS value
 document.images[i].style.width = 'auto'; //setting CSS value
// document.images[i].height = ''; (don't need this, would be setting img.attribute)
// document.images[i].width = ''; (don't need this, would be setting img.attribute)
}