How to build a online photo editor

I want to make an online photo editor on my website I have knowledge of only HTML and CSS. Please guide me which language I should learn or what should I do to make my online Photo editor. Thank You

C++, JavaScript (with jquery)

Can You help me by giving a particular topic in c++ and javascript from which I can build my Online Photo editor step by step. Help me getting started as I am totally new to C++ And JAVA

Never used Java or C++, but i noticed how they are used to be very simple when it comes to back end programs that could be like making a photo editor. If you were doing this Front End than you would use JavaScript i would say:

Front-end: Websites, and the code beneath

Backend: Like making a video game, but makes complex tasks JavaScript cant handle easier

Id recommend asking someone (@), or making a topic (Should i use C++ or Java for a photo editor) to ask.

canvas photo editor html5