Simple Pixel Doubling?

Corpsecreate · 22nd December 2011, 13:17

I have a 640 x 480 clip and I would like to directly duplicate the resolution to 1280 x 960 by duplicating each pixel. I imagine this would cause no artifacts and would be a very fast resize. Is there a resizer that can accomplish this? Also is there a way to halve the resolution by removing every 2nd pixel (ie go backwards from the upscale)?

Any help is appreciated ;D

sneaker_ger · 22nd December 2011, 13:27

PointResize() ?

TheFluff · 22nd December 2011, 13:33

Doubling the resolution in both directions is pixel quadrupling, but yes, pointresize() will do that. For the other direction you can use either pointresize() again or reduceby2().

Corpsecreate · 22nd December 2011, 13:37

Thank you very much for the help. I did a quick test by subtracting the pointresized image from the original and I get a complete grey image as expected. When I used reduceby2() to go backwards I got a slightly blurrier picture with edges showing up on the subtracted image. Thanks for the help guys!!

Edit: Another quick question if I may. When it comes to Spline36 vs Lanczos4, which is faster to process? I wont ask which one looks 'best' because thats subjective but one should be faster than the other.

Gavino · 22nd December 2011, 15:23

Quote:

Originally Posted by Corpsecreate

When I used reduceby2() to go backwards I got a slightly blurrier picture with edges showing up on the subtracted image.

Yes, ReduceBy2() does anti-aliasing and blurs the image -it's similar to BilinearResize in effect.
Using PointResize will losslessly restore the original image.

Quote:

When it comes to Spline36 vs Lanczos4, which is faster to process? I wont ask which one looks 'best' because thats subjective but one should be faster than the other.

Spline36 is faster as it processes fewer pixels (equivalent to Lanczos(taps=3)).
Lanczos4 is the same speed as Spline64.

22nd December 2011, 13:17	#1 \| Link
Corpsecreate Registered User Join Date: Oct 2011 Posts: 23	Simple Pixel Doubling? I have a 640 x 480 clip and I would like to directly duplicate the resolution to 1280 x 960 by duplicating each pixel. I imagine this would cause no artifacts and would be a very fast resize. Is there a resizer that can accomplish this? Also is there a way to halve the resolution by removing every 2nd pixel (ie go backwards from the upscale)? Any help is appreciated ;D

22nd December 2011, 13:37	#4 \| Link
Corpsecreate Registered User Join Date: Oct 2011 Posts: 23	Thank you very much for the help. I did a quick test by subtracting the pointresized image from the original and I get a complete grey image as expected. When I used reduceby2() to go backwards I got a slightly blurrier picture with edges showing up on the subtracted image. Thanks for the help guys!! Edit: Another quick question if I may. When it comes to Spline36 vs Lanczos4, which is faster to process? I wont ask which one looks 'best' because thats subjective but one should be faster than the other. Last edited by Corpsecreate; 22nd December 2011 at 13:51.

22nd December 2011, 13:27	#2 \| Link
sneaker_ger Registered User Join Date: Dec 2002 Posts: 5,565	PointResize() ?

22nd December 2011, 13:33	#3 \| Link
TheFluff Excessively jovial fellow Join Date: Jun 2004 Location: rude Posts: 1,100	Doubling the resolution in both directions is pixel quadrupling, but yes, pointresize() will do that. For the other direction you can use either pointresize() again or reduceby2().