Please download the scanner driver for your PIXMA MX532 from Canon's web site.
To access the downloads, please use this link:
Once on that page, please click the Select button to the right of "ICA Driver" and then the Download button.
When the download is complete, please click on "misd-mac-ijscanner14s-4_1_3-ea21_3.dmg" in your downloads folder to install the driver on your computer.
You can also click on the Software tab of that web page to download and install the "IJ Scan Utility". This application can be used to scan with your PIXMA MX532 once the ICA driver is installed.
For more information regarding the IJ Scan Utility, please use this link: