How might I refresh high school level mathematics and extend it much further?

I did well at Mathematics at school (top 0.1% in the country, approximately), however I stopped studying it when I was 16. Since then I've studied a couple of highly specific mathematics modules in university (primarily matrix manipulation) however these weren't taught clearly.

My current mathematical knowledge only really amounts to addition, subtraction, multiplication, division (not long division), fractions, decimals, percentages, and a bit of algebra. And the odd things about angles, but just the basics. I have certainly studied further than that, but I need a serious refresher!

I'd like to progress from this fairly basic level to having a solid mathematical understanding, with a view to both improve myself as a programmer and to meet the requirements to start a Masters degree in Computer Vision/Imaging in two years. (While this is my specific goal, I'd also enjoy learning mathematics in general for myself.)

I'd ideally like to learn from a textbook or other written resource (I find it much easier to read than to listen to an explanation) and I'd ideally like some problems to solve to ensure I understand the material. I'm happy to buy a textbook (or several), but where to start?

Summary -

Progress from basic high school level -> Computer Vision/Imaging related mathematics.

Written resources rather than video. Happy to buy a textbook.