What does Upscale DVD to 1080p in home theatre mean?

Answer 1

Standard definition video uses either 480 or 576 lines to create an image. HD video uses 1080 lines.

A DVD upscaler is a device that takes a 480 or 576 line image and re-sizes it to fill a 1080 line screen. The output of the DVD player will therefore be HD. But... this does not mean the DVD has become a high definition movie. The original detail was stored in the lower number of lines. Spreading the detail across more lines does not increase the image resolution in any way at all.

All flat screen televisions also have a scaler. The screen is made up from a fixed number of pixels. 1920 by 1080 is common for an HD television. That means that all incoming video must be re-sized to that number of pixels to fill the screen. If SD video is fed to the television, it will be upscaled or re-sized in the same way as the DVD player does. The end result is still a 1080 line image with 480 line quality.

Many televisions don't have a full 1080 line display. There are models that have 1050 lines or 768 lines. Consider the use of a DVD up-scaler with a 768 line display: The image is scaled from 480 lines up to 1080 lines. There are bound to be some losses in this process, however minor. The television will receive a 1080 line image and will re-size it back down to 768 lines to fit its own screen. There will be more losses in this second re-size process. In this instance, it is unlikely that using the DVD up-scaler will have any positive impact on the image quality.

A final note: Not all re-size engines are made equal. Some can operate better than others so it is worth trying the DVD upscaling process and comparing it to feeding standard definition into the television. It is quite possible that you may prefer one image over another. If so, the the one you prefer is the best route to take.