There is a useful tool in MikTeX called dvipng, which can transform dvi file to png file.
My question is about the useage of this command. I usually use it with options
-T tight -D 120 -z 9 -bg Transparent
but sometimes pictures output are not clear enough when printed on papers,
so I increased the dpi to 1200 in order to make them more clear:
-T tight -D 1200 -z 9 -bg Transparent
Despite of it goes more clear indeed, the size of the picture, out of my expectation, increased 99 times at the same time.
I want to increase the dpi without increasing the size of the picture, so how to realize it?