You cant stop people who are intended to copy the content from your blog. But still there is one way to block copying of HTML content. Try this code to block copying of images and other HTML stuff from your blogger page.
The best way to stop people copying images is to disable the right-click option in your blogger page. You can do this simply by following these simple steps:
1. Go to "Layout->Edit HTML" from your dashboard. Always, you should make a backup of your template before modifying the HTML by clicking on the "Download full template" link at the top of the page first.
2. Search for the following code in your template.
3.Replace the above code with the following code.
<body oncontextmenu='return false'>
4. Save your template and then you may verify the "Right Click" option by yourself. It will be disabled.