blur when resizing down

[VistaXP]

I've tried to resize a movie down to 512x288, and notice that when watching to full screen it causes more blur than if I was to not resize at all. What filters should I apply in virtualdubmod to fix this?

[JohnnyMalaria]

If you are resizing to 512 x 288 and then watching full screen, you will always see blurring - you have thrown away the detail!

Can you provide more information? Video format (MPEG etc), what your full screen is (are you playing back on your computer or watching on TV)? What is the original video source (e.g., camcorder, DVD etc)? Why are you wanting to reduce the size in the first place?

[manono]

Yeah, I agree. 512x288 is small enough that when viewed fullscreen on any decent display, it just won't look very sharp. The quality of your resizer also plays a part. Lanczos will be better than Bilinear, for example.

[edDV]

I've tried to resize a movie down to 512x288, and notice that when watching to full screen it causes more blur than if I was to not resize at all. What filters should I apply in virtualdubmod to fix this?

VistaXP,

Think about it. Why is this picture blurry?


Add to that all the 1/2 motion resolution from dropping a field and encoding artifacts.

Here is a bit of bilinear upscale filtering with Photoshop.

[JohnnyMalaria]

Hey, that's my monkey!

Here's part of the original image:



(a still image from a Sony DSR-PDX10 3CCD camcorder - 1152 x 864)

If you are dropping a field (the 288 is a giveaway!), you'll get better results keeping the vertical size the same but reducing the horizontal (if you must) - e.g., 256 x 576. Many moons ago - when 100MB hard drives were *the* thing, I would capture to MJPEG at half-width, full-height. It looked a lot better than half-height, full-width since the latter effectively throws out one field. Playing back on a TV, each scan line was effectively duplicated, making the video look very low resolution.

[VistaXP]

I'm converting a dvd to xvid avi.

If I keep it at normal size (larger), will it take longer to encode? Or will he be the same?

[edDV]

I'm converting a dvd to xvid avi.

If I keep it at normal size (larger), will it take longer to encode? Or will he be the same?

Normal size will require more bitrate to maintain picture quality.

You can experiment with a clip to see which frame size gives an adequate full screen playback on your TV, then experiment with bitrates. The higher the bitrate, the better it will look.

[manono]

If I keep it at normal size (larger), will it take longer to encode? Or will he be the same?

Compared to 512x288? Much longer to encode. As the number of pixels increases, so does the encoding time.