I want to do PhD but I am confused to choose a topic. Do we have to decide a specific topic by ourselves or we just have to decide a field like cloud computing or digital image processing ? please do reply fast. Thank you very much…

Thanks for asking an important question, I will be writing a complete post on the topic in coming days. But for general idea

1. One need to choose a topic that they understand well.
2. You can choose a broad area then go deep into it.
3. Take help from guide in narrow down research topic.