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01-21-2016, 03:00 PM   #31
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QuoteOriginally posted by Oakland Rob Quote
I've been doing homework for days, and still can't do it with standard dcraw v. 9.26 (at least the MacPorts installed version, which is the only one that runs on a Mac). As I noted above, "dcraw -s all" doesn't do it; it produces only one image. So I'd love to know the secret handshake, if in fact you've done it.
Sorry, I should have referred to dcrawps...I still think of it as just a patched dcraw.

QuoteQuote:
The FAQ at Coffin's website doesn't list the K-3II as supported, so I think it's only Tomtor's dcrawps fork that does this. That #137 post cited above has commands that do NOT separate them on a Mac as I've already noted, although it's claimed that the "standard" (which I took to mean latest, i.e. 9.26) does separate them (and used dcraw not dcrawps). Maybe "standard" dcrawps can. Given that a stray letter in command line tools can bollix up intended results, maybe a typo. Maybe the different fork. Confusing.
I haven't seen a single example of the regular dcraw extracting separate files; if I get around to finding a PC I can install dcrawps on I might try it; there's no dcrawps MacPort.
You may be right that only dcrawps is able to extract the separate files.
It's surprising that someone hasn't built dcrawps for OSX, it should be a straightforward compile.
It might be worth putting out a call on PF to see if anyone here has built it, and can provide you with the binary.


Cheers,
Terry

01-21-2016, 04:53 PM   #32
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I will report back in a few days once I have some cleaner data, but at the moment it appears that processing a SINGLE raw PEF file in DxO Optics Pro v10 is producing IQ that is comparable to a 4-channel image-shifted PEF image processed via ACR. If this is true, then a merge/blend of 3 or 4 handheld images processed via DxO would exceed the IQ of a tripod-mounted image-shifted photo processed via ACR. Stay tuned.

Michael
01-21-2016, 06:08 PM - 1 Like   #33
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I just verified that the latest dcraw from Dave Coffin available in ubuntu 15.10 can extract 4 files from a pixel-shifted DNG, as follows:

$ dcraw -s all ~/Downloads/*-psr.DNG

$ls *.ppm
YIMGP0570-psr_0.ppm
YIMGP0570-psr_1.ppm
YIMGP0570-psr_2.ppm
YIMGP0570-psr_3.ppm

The -psr.DNG was downloaded from the link provided in the Imaging Resource review of Pixel Shift.

Unfortunately I cannot compile tomtor's dcrawps using the gcc 5.2.1 version in ubuntu 15.10. The compile ends up choking on many undefined references. A lot of people are having problems with this version of gcc. Will keep trying.
01-21-2016, 11:38 PM   #34
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QuoteOriginally posted by c57d Quote
On person reported here: https://www.pentaxforums.com/forums/58-troubleshooting-beginner-help/306389-pixel-shift.html that by using DCRAWPS they pulled out 4 images but it was unknown if they were all the same or different.

You can use DCRAWPS to color the "movement area" with purple so it can be fixed: https://www.pentaxforums.com/forums/172-pentax-k-3/296497-implementing-automa...hot-dcraw.html

A little more reading about it here gives some insight into the command-line switches: https://www.pentaxforums.com/forums/172-pentax-k-3/304968-pixel-shift-may-actually-winner-5.html

I think a viable workflow would be to take a RAW+JPEG. Clean up the raw file using PDCU as noted here: Pentax K-3 II Review - Processing Pixel Shifted RAWs | PentaxForums.com Reviews

Then layer it with either the jpeg or an image pulled out from DCRAWPS and brush out the bad parts and flatten your image.

Note that there may be issues with shooting DNG or PEF as noted here: Some results from the K-3 II: Pentax SLR Talk Forum: Digital Photography Review

I'll have some time this weekend to test it if nobody reports back their try by then.
.

Layering the Pixel Shift RAW with the jpg produced in camera when the photo was taken will not work. The jpg image contains the same artifacts as the pixel shifted RAW image.

01-22-2016, 10:40 AM   #35
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Stop the presses!

I took note of jbinpg's success and tried an Imaging Resource DNG instead of one of my own. The non-PS regular ol' dcraw -s all pulled out all four from within that image. Now on to the mystery of why it didn't work on my own.

EDIT: aargh. Mea culpa; my test pixel shift was apparently shift-borked, probably in the process of various testings and such in Lr, where maybe I ran it through the DNGerator or something. This command is working fine in the Coffin fork of dcraw (and I'm using the MacPort's version, easily installed through MacPorts on a Mac:

dcraw -s all /path/to/yourPixelShift.dng

Add a -T if you want Tiff output instead of PPM.

Again, shoulda caught this earlier. Should we have a separate Pixel Shift FAQ, thread, or something like that for this? Lots of the posts in PS threads are conjecture, outdated, or experimentation, and things have progressed. It's tough to search on this, hence maybe a separate location for this? I'm not even sure if it's a PP thing or K3II thing, especially if other new cameras get the tech.

Last edited by Oakland Rob; 01-22-2016 at 10:49 AM.
01-22-2016, 11:04 AM   #36
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A pixelshift guide detailing all of this would be a great feature for the home page, IMHO...
01-22-2016, 07:00 PM - 1 Like   #37
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OK. I finally compiled dcrawps (nothing wrong with the source code, all user error) and ran some tests. It works as advertised.

I will set up a folder on my Dropbox and put the files there to show what can be done. The 16-bit tiffs are 145 megabytes each so can not be uploaded to PF without sacrificing the detail. I will include a text file in each folder explaining the command line used to get the resultant image.

Until I get the Dropbox set up, here is a summary of the process:

1) Downloaded YIMGP0570-psr.DNG from Imaging Resource Pixel Shift review article of Pixel Shift at

Pentax K-3 II Review: Now Shooting! - Gallery

Note: you need the -psr file(s).

2) Ran dcrawps on the DNG to get an idea of how much motion there is in the image as follows:

dcrawps -X -G 20 -T -4 -w YIMGP0570.DNG

dcrawps works by comparing the two green channel readouts and computing any difference in pixels. The percentage difference threshold is controlled by the -G switch so the above command sets the threshold to 20%. The -X switch highlights those 20% of pixels in purple. The -T switch ensures tiff output, -4 ensures a linear tiff, and the -w switch ensures that the conversion will be done using the camera white balance. The last two are just my personal preferences for tiff output from dcraw since I take the tiff into another program for final post-processing.

I have attached a series of 8-bit reductions of the results of the following highlighted pixel tests (top to bottom image):

a) dcrawps -X -G 10 -T -4 -w YIMGP0570.DNG (file: YIMGP0570-psr_10pc.resized.jpg)

b) dcrawps -X -G 50 -T -4 -w YIMGP0570.DNG (file: YIMGP0570-psr_50pc.resized.jpg)

c) dcrawps -X -G 90 -T -4 -w YIMGP0570.DNG (file: YIMGP0570-psr_90pc.resized.jpg)

Note how the lower the pixel threshold, the more pixels will be highlighted which makes sense. If you use a 1% threshold, you will see that thermal turbulence from an apparently static object is enough to trigger a purple pixel.

I will send another post showing the repair capability of dcrawps to keep post sizes down.

Jack
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01-22-2016, 07:27 PM - 1 Like   #38
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Here is a summary of the repair capabilities of dcrawps which has the ability to replace detected pixels over a certain threshold and replace them with unshifted pixels from the first raw bayer image.

The command line to trigger the repair is the same as to check the motion-detected pixels *minus* the -X switch.

dcrawps -G 30 -T -4 -w YIMGP0570-psr.DNG

However, you need to adjust your thinking for which way you need to go with the threshold. If you give it a high threshold such as -G 90, you will not repair all of the high-movement areas. Instead, you will need to use the other end of the scale such as -G 20. For more repairs, you need a lower threshold.

Here are a series of 8-bit reduced files showing the difference in the various -G settings. Keep an eye on the right hand side of the rightmost flag.

The series starts at -G 30 and works its way down through -G 25, -G 20, -G 15, and finally -G 10. The sweet spot to my eye is around -G 20.

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01-22-2016, 08:30 PM   #39
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I'm just viewing on a Surface Pro as I sit in a hotel room. I can definitely see the repairs to the right flag being done in the first two and the third looks good. What I can't quite tell is what gets "worse" in the last two examples. Can you point out some things to look for?

I'm really digging this thread and like what I'm seeing. I really look forward to getting a K-3 II and want to use it a lot for landscape shots. It will be really nice to be able to identify and "fix" some minor imperfections.
01-23-2016, 03:02 AM   #40
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Nothing gets worse. Itis just that there is a point where a lower threshold brings no further improvement. Keeping the repair threshold as high as needed keeps the pixel-shifted pixels around instead of being replaced by bayer interpolated ones.
01-23-2016, 10:34 AM   #41
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In non-PS dcraw there are no -X and -G functions. Here's the same DNG run through with the other options and resized. It looks like it uses one of the four.Name:  YIMGP0570-psr.jpg
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01-23-2016, 01:17 PM   #42
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All this dcraw stuff is way above my head. I need more than a couple of posts demonstrating how it's done. Also, it seems to me to be far too much messing around in post with specialty software to correct this problem.

A YouTube video detailing how to install and use this dcraw to get rid of movement caused artifacts on pixel shifted images would be much more helpful. In fact, I'd pay to watch a good YouTube tutorial on the subject (and suspect others would too).

Why doesn't Pentax/Ricoh publish such an instructional video? Maybe the reason they have not done so is because the next generation of their cameras (e.g. K1) will have this addressed on camera with improved firmware? Or, maybe Pentax/Ricoh are going to release an updated version of their "Digital Camera Utility" (the software that most of us use to process RAW pixel shifted images) that will have a simplified version of this process included in it?

Last edited by Fenwoodian; 01-23-2016 at 01:43 PM.
01-23-2016, 01:45 PM   #43
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It would be really nice if this could be implemented as a "slider" where you could see the effect of changes in the threshold in real time.
01-23-2016, 06:59 PM   #44
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QuoteOriginally posted by Fenwoodian Quote
All this dcraw stuff is way above my head. I need more than a couple of posts demonstrating how it's done. Also, it seems to me to be far too much messing around in post with specialty software to correct this problem.

A YouTube video detailing how to install and use this dcraw to get rid of movement caused artifacts on pixel shifted images would be much more helpful. In fact, I'd pay to watch a good YouTube tutorial on the subject (and suspect others would too).

Why doesn't Pentax/Ricoh publish such an instructional video? Maybe the reason they have not done so is because the next generation of their cameras (e.g. K1) will have this addressed on camera with improved firmware? Or, maybe Pentax/Ricoh are going to release an updated version of their "Digital Camera Utility" (the software that most of us use to process RAW pixel shifted images) that will have a simplified version of this process included in it?
It's not really that tough. I just typed about four words, dropped a file on Terminal, and it spat out the photo above. And the included (but crapware) DCU produces very nice images from pixel shift, as does Lr/Ps via Adobe's RAW converter. And so does the camera: it can spit out a very nice JPEG.

All of this discussion is a about doing post on images with MOVEMENT, which is NOT something that should be in your pixel shift images. We're trying to find ways to mess with that.
01-23-2016, 11:08 PM - 1 Like   #45
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Correct. The above image has a car moving into the image and a flag waving around in the wind. Rather than toss it out as unsalvageable, dcrawps allows you to remove the artifacts of movement and rescue it. I fully agree that it would be much easier for those unfamiliar with the command line to have a GUI with sliders and I would not be surprised if such is developed in the future.

If there is anybody wanting to see more detailed full size dcraw tiffs, please send me a PM and I will send you the Dropbox link.

Jack
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