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Cannot this scaling and line doubling be perfectly done by a computer? I've been told it is possible. I don't understand about computers or electronics. I only want to get the best image for a projector and I've been told that a computer is the best choice to scale a DVD source ( or any other ) to the resolution of the projector. Can anyboy explain me what ¨scale¨or ¨doubling image¨is? Thank you.
 

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Doubling in its simplest form is scaling to twice the number of scan lines. In current video terminology, doubling refers only to converting interlaced NTSC or PAL to progressive scan.


Plain doubling of interlaced video produces a picture that leaves a lot to be desired. This is because each video fiield has only half the detail (vertical resolution) of the picture. It is as if the fields must be used in pairs but it is really more complicated than that The term "de-interlacing" is also used, especially to refer to doublers that take parts of adjacent even and odd video fields to make the best quality video frames, as opposed to just spit out each scan line twice. Even combining each odd field with the next field in its entirety is not the best.


Scaling refers to reformatting the picture to occupy a different number of scan lines. If the original source is interlaced video, the best results are obtained by doing good de-interlacing to progressive scan first and then scaling to the final desired number of scan lines. In the context of scaling, each video frame stands alone, not needing consideration of the preceding or next frame, thus performing the scaling just needs duplicating or dropping one scan line every here and there, preferably using some blending with neighbors.


All doublers and scalers employ digital processing and have a built in computer. Except for those film source video materials where the first of each pair of matching fields is flagged, no computer can do a perfect job of de-interlacing. As far a scaling goes, what is better or worse is to some degree subjective.


For simplicity,doublers and scalers have just a small finite number of scaling choices. With a personal computer, you can get software that offers more choices including continuously variable scaling.


Video hints:
http://members.aol.com/ajaynejr/viddoubl.htm
 

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Jose,


Computers can indeed be used as scalers. That's exactly what "The Rock" scaler is, but they've included their own proprietary hardware and software to try to make it better than what you can do on your own.


Being able to combine a DVD player and scaler technology in the same box is one reason why AVS' Home Theater Computer forum exists. While several companies, including AVS, will sell you a preconfigured HTPC, persuading it to work optimally with your display can be a daunting project.
 
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