Maybe you could try Adobe Professional to convert PDF to .doc file and see if that will work, but maybe it won't since PDF is not supposed to be edited. Maybe it would be easier if you would type the equations directly in word with Insert > Equation. It is quite user-friendly. Good luck.

Hi d'Almeida; I tried it but I note the equation changing format. So far, use direct input method in Microsoft word. But I want to get faster way. thanks.

I would use Shift-Print Screen to capture a screen image, then use Photoshop or other editing software to crop the image.

But make sure you have copyright permission to use part of someone else's paper (assuming it is not your own). Better to recreate the equation yourself.

Well, you can try InftyReader. However I've never used it so I don't know how it works and if it would work. I still think that it would be easier and faster to write the equations directly.

Dear Marek; this way I cannot equation edit because it's image!

Is there a way to convert the image to equation text ?

regards

Dear d'Almeida, I will look for this program and try it. thanks

InftyReader is a suitable tool to convert your snapshot image (e.g. PNG format) to math-type. The following link shows the steps:

https://www.youtube.com/watch?v=HuTbXDA9YiU

Dear Alyan, thank you very much.