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Posted by Jan Panteltje on 12/26/06 18:57
On a sunny day (Tue, 26 Dec 2006 12:49:59 -0500) it happened "Steve"
<no@mail.sorry> wrote in <ahdkh.10$9m7.1@newsfe11.lga>:
>Dear Jan,
>
>I took a look at a higher-end Mustek (5Mpixels) mp4 camera and found that
>the VIDEO RES is 640x480. See below...
>
>a.. Stylish 6-in-1 digital video camcorder with 12-megapixel resolution and
>10x digital zoom
>a.. 5-megapixel CMOS sensor; MPEG-4 video formatting with 640 x 480
>resolution @ 30 fps
>a.. 2.0-inch TFT LCD display; 32 MB internal memory; SD/MMC memory card slot
>a.. Also functions as digital camera, digital voice recorder, MP3 player,
>and card reader
>a.. Measures 1.61 x 2.91 x 3.86 inches (W x H x D); 1-year limited warranty
>
>http://www.amazon.com/Mustek-5-0-Megapixel-MPEG-4-Digital-Camcorder/dp/B000E263YG
You fail to see the point that _ANY_ cut-out of the sensor is _always_
rescaled to 640x480 (in mpeg4).
So:
case 1, digital zoom at 1x, i use the whole sensor:
I grab 2048x whatever and rescale it to 640x480 in soft, and then encode to mpeg4 640x480.
case 2, digital zoom so I use 640x480 of the sensor:
I grap 7640x480 from the middle of the sensor, no need to rescale, encode to mpeg4 640x480.
case3, digital zoom 8x, I use the smallest possible area of the sensor:
I grab 2048 / 8 = 256 x whatever from the middle of the sensor, rescale up to 640x480,
encode to mpeg4 640x480.
Always the output format is 640x480 of course, as you noticed.
The only time when the Mustek I have does _nopt_ use full 2048xsomething i n1x zoom, is
when it has motion stabiliser activated.
In that case it uses about 10% less (you can clearly see the picture shrink a bit when
you activate it).
In case of image stbilisation it neds the extra percents to move about to keep it centered.
This is all very simple and all there is to it.
>I suggest you capture a bit of video in what you believe to be the camera's
>highest resolution, then examine the file on your PC, in whatever
>application you have, and check it's properties to learn it's actual
>resolution.
F*cking arrogant remark!
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