Falling into another Wabbit Hole... [part Four]

I've gone from the Already Known, to the Mildly Interesting, and onto the Absurdly Ridiculous. With this entry I run headlong into the Certifiably Insane.

I'll make one last pass at image up-sizing.  This time I'm going to try and quadruple the area of an image by going from 24mpixel to 108MegaOutragiousHolyMolyBatmanDearGawdAlrightyPixels.  In the process, my poor 'ol Linux image processing 'puter will be super stressed and might just eel over, paws up.

The process of upsizing will be done in steps and by hand so that each stage is known and understood.  That way if I want to modify or substitute something different at any of the steps I'll have all the Points of Reference needed to properly evaluate an outcome.

This is in contrast to software providers who's products pretty much hide what's going on behind the marketing hype of "AI."  I can't for the life of me understand how these kind of software are "AI" driven, if they mean by AI Artificial Intelligence.  Where is the Promised Land of Machine Learning when the current state of what's called "AI" gives wrong answers?  Seems like a willfully stupid machine if you ask me and "AI" could actually stand for "Absurdly Ignorant" for all I know.

OK.  I'll step off the soapbox... um... yes... photography... make big beautiful picture bigger.  That's it.  I'm back, now.  Ack! what a detour.

 A photograph of simply the most
beautiful Fezzaz racecars ever constructed.
Captured using a Sony A7 and Sony 35mm f/2.8 ZA.
On a tripod, of course.  How else do you get
something like this ridiculously sharp in low
light at ISO100 and the lens set at f/8?

Multi-image-file averaging (3 file image stacking), even at low ISO, produces for what I've seen so far coming out of my nearly 10 year old Sony A7 Full Frame cameras Super Clean Noiseless files.  Applying a bit more sharpening on a 1.5x linear upsize returns cleaner files at 9000 pixels long than I ever ever got out of my old Canon 5D MkII DSLR at base 5616 pixel image size.  

From what I've experienced, sensor technologies have come a long ways and I feel Sony is currently in the lead.  Since Nikon used/uses Sony sensor foundries for their light capture devices, I'll include Nikon in a sub-heading to Sony's sagesse in this area of design and manufacturing.  In fairness, though, I read somewhere recently that Canon may have caught up with Sony with Canon's latest iterations of the R-series Full Frame cameras.  So don't take my word for anything and test for yourself.

 

Setup ~

Again, using Human Intelligence (HI!!!) to capture three images to stack as a noise reduction and file upsize exercise -

• Sony A7
• ISO100
• 2second timer
• Back-button focus (to maintain image alignment - focus once, shoot three)
   
• Sigma 24mm f/3.5 DG DN
• Set to f/8
   
• Manfrotto tripod
• Rawtherapee
• Curves setting
• Capture Sharpen
• Noise Reduction
• Kodak film emulation
  

• Gimp
• 3 image stacking in layers
• Opacity setting of layers
• Scale Image NoHalo image upsize operator - sample size 1200DPI (this is important)
  
• Additional sharpening application (various G'Mic integrated operators)
  

To reiterate, the file upsize filter set to either 600DPI or in my case 1200DPI is important because it sets the number of "slices" of information per inch that the upsize will take during the operation.  Regarding the upsize algorithm, I've previously written about the NoHalo.  I won't cover that again here, except to note it's much better than anything else I've to this point tried.

 

Comparison

[As always, click on the following image and inspect it at 100percent to see whatever there might be to see]

For this exercise I will consider the final set of rows in the following image. They are the ones upsized to 12000 pixels on the long dimension.

 

 

Comments ~

Keep firmly in mind that I'm taking a 24mpixel image and upsizing it to an effective 108mpixel.  I'm _not_ adding any information that's not already in the original base image.  I'm simply taping and mudding over the empty spaces in what I feel is the best manner possible to make things appear sharp and acceptably printable.

 

You can see the basic upsized three image non-noise reduced averaged sample is smooth across the field.  There is detail where we want it and nothing looks too pixelated.  If you look hard enough you will find a wee-bit-o-pixelation, but it's certainly not "bad" by any means.

Sharpening the non-noise-reduced upsize reveals more pixelation.  This is offset by increased local contrast.  Depending on the printer we might only see the pixelation on very close examination.

I did a second 108mpixel upsize pass, this time using the noise reduced files to stack and then resize.  I think I'd go crazier than I already am trying to find significant differences between the two image stack approaches.  Noise reduction or noise cancelling simply works.

OK.  OK.  If I squint, stand on my left leg, curl my right pinky, and howl at the Full Moon when it's in conjunction with Saturn maybe I can see just a hint of more smoothness out of the noise-reduced three image stack upsize.  But as I said, any differences are really quite insignificant.

Just how Gud(tm) all this is can easily be seen when comparing these 108mpixel upsized works against the well processed and very lovely 24mpixel image viewed at 200 percent.  This is seen in the very last row in the comparison. 

 

In terms of print size while retaining as much "image quality" as possible, 300DPI prints from this 108mpixel file reach 40inches.  Returning to one of Thom's thoughts on print sizes and DPI, and using his lower end of 188DPI (I can't find the original article, but he mentions somewhere else that 188DPI is very printable on Epson), we get a good resolution 64inch long print.  Whew! 

 

If you're interested, ask me sometime how we used to print 40x60inch from 35mm negatives when I worked at Samy Cameras Crossroads to the World print lab.  I have a few thoughts on the Current State of Things, print sizes, and viewing.

As a side note, this is as big a file as my little Linux laptop can handle.  I have to close everything but the Gimp when performing the upsize and sharpening operations.  Nothing can be in memory.  All non-essential processes have to be closed for this thing to successfully run the Richardson Lucy G'Mic sharpen algorithm.  If there's a leftover process running somewhere in the background, 108mpixel is too much of a burden and the Gimp gracefully, but firmly closes from an Indeterminate State.

... hmmm... I've been thinking about a new HP 4k UHD i7Core 32gb RAM laptop... maybe I have good reason to pick one up...?   Nah... but perhaps...

 

Yes.  This has been fun. It really has.  But this is it.  I swear.  I'm finished.  No more upsizing.  No more Wonderland.  No more Dead Pope Society stuff.  No more Del Orto tuning. Nutt'n.  Done.  Put a fork in me.  I'm cooked.