Forums > Jitter

Upsampling Pics

December 9, 2008 | 2:59 am

I’ve made a number of 1280 x 960 .BMPs with Print Screen Deluxe by
taking frames from an animation at full screen . (my monitor is 1280 x
960 x 72 dpi). I want to print these images large at 5120 x 3840 x
300 dpi without any noticeable pixelization. I’ve modified the
42jSlab-Readback.maxpat somewhat in my attempt but it’s not working
yet. See below. This is probably a no-brainer for some but I’ve been
on it for a few days and I’m stuck. I will appreciate any help anyone
may offer. TIA

Cheers, Chuck Henry

– Pasted Max Patch, click to expand. –

December 9, 2008 | 5:20 am

I havent looked at the patch, but you may be hitting graphics card limitations, only really new cards have texture sizes larger than 4096×4096 = 16,777,216 pixelx, you want 19,660,800 pixels, which might be an issue… ;)

Why not use Photoshop/GIMP or something like that, were you will have more control over the image scaling algorithms?


December 9, 2008 | 7:50 pm

Hi Vade,
I think you are right about the limits of the graphics card limits.

I have been able to upsample to 3840 x 2880 x 130 pix/in = 11,059,200
in Jitter with the patch I posted.

I did try Gimp before and again last night … and at 6600 x 8801 x
299 pix/in … scaling also seemed to retain the pixelization on the
edges of the spheres even with antialiasing.

Comparing the three cropped images attached, I thinking that the
scaling is not removing the edge jaggies … it is only smoothing the
surfaces.

Any more thoughts are appreciated.
Cheers, Chuck Henry


December 10, 2008 | 4:43 am

Hi Vade,
I think you are right about the limits of the graphics card.

I have been able to upsample to 3840 x 2880 x 130 pix/in = 11,059,200
in Jitter with the patch I posted.

I did try Gimp before and again last night … and at 6600 x 8801 x
299 pix/in … scaling also seemed to retain the pixelization on the
edges of the spheres even with antialiasing.

Comparing the three cropped images attached, I thinking that the
scaling is not removing the edge jaggies … it is only smoothing the
surfaces.

Any more thoughts are appreciated.
Cheers, Chuck Henry


December 10, 2008 | 1:33 pm

Just as a general principle, if you are upscaling individual stills, you’ll get better results from a dedicated upscaling program like Genuine Fractals or even QImage (which is able to render upscaled images, not just print).

Video upscaling, what you see in upscaling DVD players and such, uses information from multiple consecutive frames to achieve better upscaling results.

I am not sure, but it sounds like you are upscaling non-consecutive stills, so video upscaling techniques might not be appropriate.


December 10, 2008 | 5:44 pm

Hi Chuck,

Chances are that upsampling low res images like these to high res
images isn’t going to produce great results.
I think you really want to re-render the frames again in either a
large window (larger than your screen size), or using a large texture
with capture set somehow, and FSAA enabled when rendering. Randy
Jone’s render node patch (http://2uptech.com) is a great example,
though perhaps overkill for your needs. There are also various ways to
readback from a window or a texture without using a screen capture
utility (which will let you capture from larger windows than your
monitor or textures which have been rendered to). Here’s one thread
from the forum:

http://www.cycling74.com/forums/index.php?t=rview&th=34799

Hope this points you in the right direction.

-Joshua

p.s. On OS X, the software renderer s quite good, and can render very
large images with antialiasing, shaders, etc. directly to a matrix,
but on Windows, Microsoft’s software renderer isn’t as full featured.


December 11, 2008 | 5:24 pm

Hi Gian,
Thanks for the tip … I’ve got the demo of QImage now and I’m going
to give it a try. It looks promising.
Cheers, Chuck

—–Original Message—–
From: jitter-bounces@cycling74.com
[mailto:jitter-bounces@cycling74.com] On Behalf Of Gian Pablo Villamil
Sent: Wednesday, December 10, 2008 8:33 AM
Subject: [jitter] Re: Upsampling Pics

Just as a general principle, if you are upscaling individual stills,
you’ll get better results from a dedicated upscaling program like
Genuine Fractals or even QImage (which is able to render upscaled
images, not just print).

Video upscaling, what you see in upscaling DVD players and such, uses
information from multiple consecutive frames to achieve better
upscaling results.

I am not sure, but it sounds like you are upscaling non-consecutive
stills, so video upscaling techniques might not be appropriate.


December 11, 2008 | 5:46 pm

Hi Joshua,
Thanks for your thoughts on this upsampling issue. I’ve got Randy
Jone’s render node patch and I’m trying to figure it out. There is not
much to instruct me though. I feel like I’m given the rulebook for 3D
chess and placed in the Olympic finals. Rerendering is on the to-do
list The limits of my hardware and the timing delays inherent in
high-res rendering pose some trial and error hurdles. Anyway I’m
working on it.
Thanks again, Chuck

—–Original Message—–
From: jitter-bounces@cycling74.com
[mailto:jitter-bounces@cycling74.com] On Behalf Of Joshua Kit Clayton
Sent: Wednesday, December 10, 2008 12:45 PM
Subject: Re: [jitter] Re: Upsampling Pics

Hi Chuck,

Chances are that upsampling low res images like these to high res
images isn’t going to produce great results.
I think you really want to re-render the frames again in either a
large window (larger than your screen size), or using a large texture

with capture set somehow, and FSAA enabled when rendering. Randy
Jone’s render node patch (http://2uptech.com) is a great example,
though perhaps overkill for your needs. There are also various ways to

readback from a window or a texture without using a screen capture
utility (which will let you capture from larger windows than your
monitor or textures which have been rendered to). Here’s one thread
from the forum:

http://www.cycling74.com/forums/index.php?t=rview&th=34799

Hope this points you in the right direction.

-Joshua

p.s. On OS X, the software renderer s quite good, and can render very

large images with antialiasing, shaders, etc. directly to a matrix,
but on Windows, Microsoft’s software renderer isn’t as full featured.


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