Transferring from standard definition to high definition is not a good idea because your increasing the size of a video by blowing it up. This method is also known as up converting.
A standard VHS, VHS-C, Hi8, Regular 8 video tape has a standard definition (SD) frame size of 720X480. High definition (HD) frame sizes are typically 1920X1080. There are some other HD sizes as well, for example: 1280X720 or the older format 1440X720 (which is rare now a-days). 1920X1080 can also be written as 1080p and 1280X720 can be written as 720p. These numbers represent how many pixels are placed horizontally and vertically on a screen.
As you can see from the numbers mentioned, SD is smaller than HD. So in order to make your footage HD, you have to increase the number of pixels on the SD format which is not available. However, if one were to do this, the computer will be forced to fit the footage over the new frame size, much like a photocopier making an image larger to fit its new larger size. This will make the image blury and fuzzy, and the quality will be reduced. Especially with today’s sharp image screens, its flaws shows up more apparently than on older television sets.
If you need to present the content in HD format, I will personally keep the size at 720×480 and have a black box around the image instead of blowing it up, which will reduce your quality.
Image srouce from: “http://static.gamespot.com/”