Unfortunately, the Windows Installer UI does not support transparent checkboxes. You have a few options:


Move the checkbox to a location that doesn't cover the background. For example, it is common to have a background in the install dialog, then a horizontal line at the bottom of the image then the buttons below the horizontal line. Putting the checkbox below the line with buttons looks good (looks standard) and can use the standard background color.
Make the checkbox control only as big as the checkbox itself then place static text next to the checkbox control with transparent background. This works but it means users must click the checkbox directly. Also, accelerator keys won't work which is an accessibility no-no. But it does look better.
Use an external UI handler to custom draw all your controls. This is easier with Burn in WiX v3.6+. The wixstdba UI can be customized using an XML "theme file". You can get a lot more custom UI than the standard Windows Installer UI supports.


It's all tradeoffs. Pick the one that works best for you.

How to Remove White Background from Wix Button and Checkbox Property?
I am looking for a way to recognize handwriting of scanned notes (in PDF format).

It doesn't have to be perfect, and it doesn't have to free, but before paying I would like to try it (even with just a single page).

It doesn't necessarily have to be a native Mac OS X application. I would be OK with an online application, or a Unix application to install or compile. In other words, anything that works somewhat decently would be OK.

I am also not necessarily looking for a perfect result. Even transforming my notes into a searchable PDF with just some of the text recognized would be better than nothing.
