Edit size of images within posts

This is a continuation of this post in which I recommend that you don’t try to edit the size of images within the posts when you add them to your post; rather, you should set the image size in the media attachment settings.

If you still want the ability to edit image sizes within posts, to create a custom image size, you can do so by changing:

img {
background: #fff;
height: auto;
width: auto; /* IE8 */
}

to

img {
background: #fff;
height: auto;
/*width: auto;*/ /* IE8 */
}

.featured-content img,
.gallery img {
width: auto;
}

For Modern Blogger Pro:

In your stylesheet, remove width: auto !important; from these sections:

img.centered,
.aligncenter {
display: block;
height: auto;
margin: 0 auto 24px;
width: auto;
}

img.alignnone {
margin-bottom: 12px;
width: auto !important;
}

.alignleft {
clear: both;
float: left;
text-align: left;
width: auto !important;
}

.alignright {
clear: both;
float: right;
text-align: right;
width: auto !important;
}

So that it looks like this:

img.centered,
.aligncenter {
display: block;
height: auto;
margin: 0 auto 24px;
}

img.alignnone {
margin-bottom: 12px;
}

.alignleft {
clear: both;
float: left;
text-align: left;
}

.alignright {
clear: both;
float: right;
text-align: right;

}

Once you have done that, refresh your browser.

Note: this adjustment is customization of your theme, and is beyond the scope of theme support. I cannot guarantee it will work with your site – I have tested it on my own sites, however.