Play pixelshift

@nosle gave permission to use his pixelshift files :slight_smile:

For that reason I want to open a pixelshift competition using one of his very good example files:

What is this contest about?

  1. Show the best result you can get out of this file while correcting as much motion as possible and preserving as much detail as possible using pixelshift with or without motion correction.

  2. Starting point is the rt default profile (not the neutral profile)

  3. Then go to raw tab, select pixelshift and make changes only to pixelshift settings.

  4. No other changes to settings in rt please.

  5. results of other software which supports pixelshift are welcome to compare (acr, silkypix, pdcu…)

Here’s my approach which also is intended to be a short tutorial:

Have a look at the details to preserve: left is amaze right is pixelshift without motion correction:

Have a look to the reduced noise: left is amaze right is pixelshift without motion correction:

But there’s a van moving through the images:

And also some other motion in the trees:

Let’s have a look at the motion mask (one of the most important things):

All pixels marked green will be taken from the amaze demosaiced frame of your choice while the other pixels will be rendered in pixelshift resolution.

Now we know where the motion is, let’s have a look what simple (but very important) green motion detection does:

There are some visible artifacts because green detection wasn’t able to dectect all motion. Let’s have activate red/blue cross and check again:

Number of artifacts is reduced but there are are sill some of them. Let’s have a look at the current motion mask again:

As you can see there are holes in the motion mask. In this holes motion is not corrected. Let’s fill the holes and look at the motion mask:

And take a look without the motion mask:

In next play pixelshift game I will also explain the smooth transitions stuff but for now I would be glad to get competitions :slight_smile:

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My final result is already saved but will be posted later :slight_smile:

I dub this the Play RawTherapee :wink:

As I mentioned, using other software than rt supporting pixelshift file is allowed :wink:

Will see what I can do with this when I find the time!

It’s worth noting the detail in the threads of the furthermost yellow tie in that first image. When I first saw it I thought it was some kind of artifacting before I realised just how much pixel shift helps resolving detail.

For anyone interested it’s also worth looking at the motion in the oblique side wall of the foreground building. The noise levels after motion correction (amaze demosaiced) compared to the surrounding pixel shifted areas are eye opening. Quite interesting technology pixel shift.

As @nosle mentioned the side wall here’s a screen shot.

As one can see there are some harsh transitions between the regions with and without motion and also some of the typical pixelshift patterns in the uncorrected region.
That’s what Smooth transitions is for. To use it one has to enable the Blur checkbox.

Left is without, right with ‘Smooth transitions’

Finally, to get rid of the remaining patterns use one step of false colour suppression. Though that’s not a tool specially for pixelshift, it often is quite useful for pixelshift images. But one has to be careful. It also can destroy some details.

Left is without false colour suppression, right is with one step.

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You’re not the only one :slight_smile: