Do you want to enhance your web page and add a customizable background image? It can be done with the plugin called Page Customizer for Woothemes Canvas
Page Customizer – premium
note: Page Customizer is a paid plugin and can be purchased and downloaded here
Step 1 Login to WordPress control panel
Step 2 Provided that you have already purchased Page Customizer and downloaded it to your local hard drive, go to Plugins > Add New
Step 3 Click Upload > Choose File then locate the Page Customizer zip file. Click Open
Step 4 Click Install Now
Step 5 Click Activate to start using the plugin
Step 6 In this tutorial, we will add a new page. Go to Pages > Add New
Step 7 Enter the page title and scroll down. You should see a Canvas Custom Settings section.
Step 8 On the Canvas Custom Settings section, click Background tab. It will show you a number of fields where you can customize the background settings.
Step 9 We will upload a new background image in this tutorial. From the background Image field, click Upload.
Step 10 Click Select Files or drag the image from your local computer to background image window then click Save All Changes
Step 11 Set your desired background settings and click Publish
Step 12 Go to your online site and notice the newly added background image. You can also change more page settings by going to Canvas > Theme Options > Canvas Extensions. Have fun!
Here is a video tutorial on how to add a background image using Page Customizer plugin