This is the action of scaling a bitmap of a given resolution to another resolution.
Stricto sensus, upscaling means going from a given resolution to an higher one while downscaling is the opposite. But most of the time, when using scaling, we're dealing with upscaling.
Why do we do that ? Because each image of a movie is encoded as a 720x480 (or 576 depending on the region) bitmap and some projectors can go much higher (no scan lines, a more detailed image ...) than that.
That's why every dvd playing application out there, and Dscaler as well, are closely linked to the notion of scaling.
Scaling is done on the fly in hardware by any recent vga card. Using this mechanism, the application has to provide the initial-resolution bitmap, and the vga card will display it at an higher resolution on its own. No cpu activity involved.
Hope this clarifies things a bit.
Stricto sensus, upscaling means going from a given resolution to an higher one while downscaling is the opposite. But most of the time, when using scaling, we're dealing with upscaling.
Why do we do that ? Because each image of a movie is encoded as a 720x480 (or 576 depending on the region) bitmap and some projectors can go much higher (no scan lines, a more detailed image ...) than that.
That's why every dvd playing application out there, and Dscaler as well, are closely linked to the notion of scaling.
Scaling is done on the fly in hardware by any recent vga card. Using this mechanism, the application has to provide the initial-resolution bitmap, and the vga card will display it at an higher resolution on its own. No cpu activity involved.
Hope this clarifies things a bit.