Yes, you may upload a background image to add text on top of using the custom image creator.
Step 1) On your intently page, click on the + sign at the lower right side and click on "Create Image".
Step 2) Drag and drop your image to "Drop your image here" in the top left, or click it to choose your image from your computer
Your new image will load to this page.
Step 3) Type your custom text on your image, choose for the text to be white or black, then click "Choose a style."
Step 4) Choose from the image styles provided and click the "Create and add to vision board" button
Step 5) Click on the vision board you want it added to and click close to complete your task. Your new image will be added to your vision board in about a minute.