Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
09-24-2017, 01:09 PM   #16
Site Supporter
Site Supporter
BruceBanner's Avatar

Join Date: Dec 2015
Posts: 5,404
Original Poster
QuoteOriginally posted by leekil Quote
If you view at more than 100%, you will get the block/pixelated effect. This is *always* the case. If you think it didn't happen before, you are mistaken. (Or maybe you are the one trolling, not everyone else trolling you?) Pixelshift increases clarity, but it doesn't increase resolution "Above 100%".
No trolling here, otherwise I am putting in a lot of effort into this troll!
I think there is just confusion over terminology here (an error on my part). What I am learning is that I have several different programs for processing RAW, CD5 (Silkypix Camera Digital 5, bundled with K-1) does the worst job of redendering the raw DNG file, and it gets worse the more you zoom in. The 100% zoom of the CD5 vs the 100% zoom of the same file in Photoshop is vastly different in what I see during editing. The photoshop version is clean with very little 'pixelation' to see at this amount of zoom, the same cannot be said in CS5, and LR is somewhere between those two programs.

The macroblocking 'square patchwork' effect seen in CD5 above on the mail box is virtually unrecognizable on Photoshop at the same zoom, and a little more noticeable but still acceptable in LR.

I've been Pixelshifting (PS) a few images this weekend and from what I can tell after reviewing the images is that the macroblocking squarepatchwork effect is part of the PS Motion correction aspect, or rather the shot was not well taken (if MC is off) and basically even a still object like a mailbox there was still somehow movement during the shot (despite a 2 second timer and ES on :S
I took PS shots of the gorge i live near on the weekend, large boulders came out fine, but the water and some tree leaves (where movement would exist) would have this macroblocking effect going on.

QuoteOriginally posted by D1N0 Quote
It's just that resolution isn't 100% on a single bayer image because of de-mosaicking interpolation.
I think i kinda understand this, but if you want to dummy that comment down I would appreciate it

QuoteOriginally posted by pinholecam Quote
You should use Raw Therapee for the PS images.

So far, its the best RAW processor for it.
The Pixel Shift Diaries

There the Squirrel Mafia RT thread on pentax forums too.
Yes, I was playing with RT last night, it's Automatic correction mode is amazing, unlike CD5 it really seems to erradicate the macroblocking effect very well whilst keeping sharpness intact on the areas of the shot that had no movement to begin with.

09-24-2017, 08:22 PM   #17
Pentaxian




Join Date: May 2016
Photos: Albums
Posts: 1,990
If you zoom in on your photo, at 100% it is equivalent to one pixel of the image on one pixel of the screen. That is the most you can zoom without seeing any pixelation artifacts. If you look *very* closely, you may be able to make out the edges of pixels on straight lines in the image, but only if you have a pretty low resolution screen or very good eyesight. If you go beyond that -- to say 200% -- then each pixel of the image is represented with a 2x2 set of pixels; pixelation here should be pretty apparent. But 100% viewing shouldn't be particularly pixelated.

BUT, on the other hand, if you don't just view your image at 200%, but enlarge it by 200% (using say, the Image Size dialog in Photoshop), then you will be altering your image to have 2x2 squares of pixels where you only had 1 pixel before. Saving this would result in obvious pixels at 100% the next time you load the image.

If you are regularly getting pixelation without enlarging the image, then post more about it and it can be diagnosed.
09-24-2017, 09:29 PM   #18
Site Supporter
Site Supporter
BruceBanner's Avatar

Join Date: Dec 2015
Posts: 5,404
Original Poster
QuoteOriginally posted by leekil Quote
If you zoom in on your photo, at 100% it is equivalent to one pixel of the image on one pixel of the screen. That is the most you can zoom without seeing any pixelation artifacts. If you look *very* closely, you may be able to make out the edges of pixels on straight lines in the image, but only if you have a pretty low resolution screen or very good eyesight. If you go beyond that -- to say 200% -- then each pixel of the image is represented with a 2x2 set of pixels; pixelation here should be pretty apparent. But 100% viewing shouldn't be particularly pixelated.

BUT, on the other hand, if you don't just view your image at 200%, but enlarge it by 200% (using say, the Image Size dialog in Photoshop), then you will be altering your image to have 2x2 squares of pixels where you only had 1 pixel before. Saving this would result in obvious pixels at 100% the next time you load the image.

If you are regularly getting pixelation without enlarging the image, then post more about it and it can be diagnosed.
Does it matter if viewing on a 1080p screen vs 4k? Like, I mean in this particular instance with the issue I'm seeing.

I pretty much feel as tho this thread has been addressed, I think two things are happening;

1) PS is a little hit and miss (at least for this guy), in that the macroblocking square patchwork effect is happening in places where it shouldn't really be, so I'm taking the shot badly at times. Recent trips and use of PS have been more successful, especially when running through RT and choosing Automatic to process. This is accounting for a large portion of my complaint that initiated the thread, it's not so much the 'pixelation' of PS, but rather the macroblocking effect that I was seeing.

2) the unwanted macroblocking is highlighted and magnified more depending upon what software interprets the RAW image and how it does that.

These two things together were confusing me, I was feeling as though some PS images looked bad from the get go, but that was in part to a combination of the two factors above.

The 'solution' to this thread (if there is one), is a) git gud (lol) and b) use RT to begin the post processing process.
09-24-2017, 10:29 PM   #19
Pentaxian




Join Date: May 2016
Photos: Albums
Posts: 1,990
QuoteOriginally posted by BruceBanner Quote
1) PS is a little hit and miss (at least for this guy), in that the macroblocking square patchwork effect is happening in places where it shouldn't really be, so I'm taking the shot badly at times. Recent trips and use of PS have been more successful, especially when running through RT and choosing Automatic to process. This is accounting for a large portion of my complaint that initiated the thread, it's not so much the 'pixelation' of PS, but rather the macroblocking effect that I was seeing.

2) the unwanted macroblocking is highlighted and magnified more depending upon what software interprets the RAW image and how it does that.
1080p vs. 4K wouldn't make a difference, other than you could maybe detect the stair step pattern of the hard edge at 100% with a 1080p monitor, but probably could not at 4K since the pixels are even smaller.


It look like there are actually two things going on:

a) in the images in your original post, any "artifact" was just normal big pixels from enlarging to > 100%. That is not an artifact related to PS or motion correction, especially because they were in areas where no motion would have occurred. These images had *no* artifact, as depicted in your post.

b) in the 200% and 400% crops of the mailbox, the artifacts you mention look like JPEG artifacts, probably which were introduced when you did the screenshots and saved then as JPEGs. And looking at the EXIF, perhaps JPEGmini might have specifically had a hand in creating those artifacts.

So I don't know what might be happening in any other PS images you have worked with, but in the ones posted in the thread, there do not appear to be an PS artifacts, as least in the crops you specifically asked about.

09-24-2017, 10:44 PM   #20
Site Supporter
Site Supporter
BruceBanner's Avatar

Join Date: Dec 2015
Posts: 5,404
Original Poster
QuoteOriginally posted by leekil Quote
1080p vs. 4K wouldn't make a difference, other than you could maybe detect the stair step pattern of the hard edge at 100% with a 1080p monitor, but probably could not at 4K since the pixels are even smaller.


It look like there are actually two things going on:

a) in the images in your original post, any "artifact" was just normal big pixels from enlarging to > 100%. That is not an artifact related to PS or motion correction, especially because they were in areas where no motion would have occurred. These images had *no* artifact, as depicted in your post.

b) in the 200% and 400% crops of the mailbox, the artifacts you mention look like JPEG artifacts, probably which were introduced when you did the screenshots and saved then as JPEGs. And looking at the EXIF, perhaps JPEGmini might have specifically had a hand in creating those artifacts.

So I don't know what might be happening in any other PS images you have worked with, but in the ones posted in the thread, there do not appear to be an PS artifacts, as least in the crops you specifically asked about.
I realise doing screenshots lessons the quality, however before posting they did accurately represent the differences in the software I was using on the same raw file and at same zooms.

If time allows I might try showing again the difference between CD5, LR and PS in illustrating the difference in what I see between the different programs, also Faststone is guilty of this also, because it's showing the Jpg preview rather than RAW? At least once you pop into LR with the raw file the colours become less vibrant and muted (so I'm guessing that's what's going on).

Could I inadvertently made this worse on myself by changing the JPG quality in the camera? For example, if I shoot RAW and not RAW+ but have every Jpeg quality setting to being as low as possible (in the camera), is this then saved to the RAW file and being used when 'investigating' the RAW file through programs such as CD5 and Faststone? I feel as though I am being duped into what appears to being a naff PS shot when viewing in such programs, but when booting said shot directly into Photoshop the image appears vastly better rendered...?
09-25-2017, 11:26 AM   #21
Senior Member
Jens Lyn IV's Avatar

Join Date: Jan 2014
Location: Ringsted, Denmark
Photos: Albums
Posts: 260
I don't agree that the macroblocking we're seeing here is the result of Pixel Shift. It shows all the telltale signs of lossy image compression. How a DNG can come to look like this is a complete mystery to me.

If possible, please upload the original DNG file somewhere. I'd love to take a look at it myself.
QuoteOriginally posted by leekil Quote
in the 200% and 400% crops of the mailbox, the artifacts you mention look like JPEG artifacts, probably which were introduced when you did the screenshots and saved then as JPEGs
If that were the case, the artifacts would be all over the screenshot, but they're only visible in the image display area; the UI looks clean and crisp, so the JPEG compression applied to the screenshot has nothing to do with the artifacts we're seeing.
09-25-2017, 08:17 PM   #22
Pentaxian




Join Date: May 2016
Photos: Albums
Posts: 1,990
QuoteOriginally posted by Jens Lyn IV Quote
I don't agree that the macroblocking we're seeing here is the result of Pixel Shift. It shows all the telltale signs of lossy image compression. How a DNG can come to look like this is a complete mystery to me.

If possible, please upload the original DNG file somewhere. I'd love to take a look at it myself.

If that were the case, the artifacts would be all over the screenshot, but they're only visible in the image display area; the UI looks clean and crisp, so the JPEG compression applied to the screenshot has nothing to do with the artifacts we're seeing.
But he's using JPEGmini to save the files. Doesn't that do a non-uniform compression on the image to get maximum compression? Less compression in the areas of more contrast and detail (the text) and more compression in the large blocky areas of the image due to the magnification.

09-26-2017, 07:01 AM   #23
Senior Member
Jens Lyn IV's Avatar

Join Date: Jan 2014
Location: Ringsted, Denmark
Photos: Albums
Posts: 260
QuoteOriginally posted by leekil Quote
But he's using JPEGmini to save the files. Doesn't that do a non-uniform compression on the image to get maximum compression?
Not to the extent of selectively lowering the resolution and grossly enlarging the artifacts, no.

Look at the screenshot again, the original upload. Here. The file being viewed is a DNG file, at 4x magnification. There are subtle JPEG artifacts in the UI, but the artifacts in the image display area are severe and severely magnified, which tells us they are somehow part of the DNG file on display, rather than being caused by compressing the screenshot.

Last edited by Jens Lyn IV; 09-26-2017 at 07:07 AM.
09-26-2017, 09:05 AM   #24
Pentaxian




Join Date: May 2016
Photos: Albums
Posts: 1,990
QuoteOriginally posted by Jens Lyn IV Quote
Not to the extent of selectively lowering the resolution and grossly enlarging the artifacts, no.

Look at the screenshot again, the original upload. Here. The file being viewed is a DNG file, at 4x magnification. There are subtle JPEG artifacts in the UI, but the artifacts in the image display area are severe and severely magnified, which tells us they are somehow part of the DNG file on display, rather than being caused by compressing the screenshot.
Except they *can't* be part of a DNG file; they must be a JPEG artifact introduced *somewhere* in the processing. I'm making my assumption going on the description of his process, and where I know there to be a JPEG file in that process. It may, however, be that somehow there is a JPEG file that is not obvious. Does flickr recompress photos? Maybe he had an inaccurate description of his processing?

---------- Post added 09-26-17 at 09:08 AM ----------

Maybe he saved it as a JPEG with the same DNG filename, and reloaded it for the second screenshot.
09-26-2017, 11:03 AM   #25
Site Supporter
Site Supporter
BruceBanner's Avatar

Join Date: Dec 2015
Posts: 5,404
Original Poster
QuoteOriginally posted by leekil Quote
Except they *can't* be part of a DNG file; they must be a JPEG artifact introduced *somewhere* in the processing. I'm making my assumption going on the description of his process, and where I know there to be a JPEG file in that process. It may, however, be that somehow there is a JPEG file that is not obvious. Does flickr recompress photos? Maybe he had an inaccurate description of his processing?

---------- Post added 09-26-17 at 09:08 AM ----------

Maybe he saved it as a JPEG with the same DNG filename, and reloaded it for the second screenshot.
It's just the DNG file open in CD5, it looks awful lol. Same file in PS or LR and it's heaps better, but I felt the CD5 did a good job of exaggerating the issues I was sensitive to seeing in LR and Faststone (as a few people here didn't seem to get what I was going on about ). If time permits I'll place the DNG file somewhere and people can go pixel peeping there, but for me this issue is resolved as far as I'm concerned. I know that through a combination of not taking the photo well vs different software interpreting the DNG file vs the JPG storing quality options in the camera may all lead to what I'm viewing in this thread. The artifacts seem PixelShifted related, seeing similar artifacts in other (PS) shots I took over the weekend and then processing in RT with motion correction set to Automatic cleared these things up.
09-28-2017, 05:59 AM - 2 Likes   #26
Pentaxian




Join Date: Apr 2007
Location: Sweden
Posts: 2,106
Yes that is jpeg artifacts, and I know why you are seeing them.

You are in "browser" mode and are thus looking at the embedded rather heavily compressed jpeg image, not the real rawdata. You can change this in the settings somewhere but not using the jpeg will slow down browsing.

The quality of the embedded jpeg seems to be size restricted (speculation) so when images have less details as in lots of blurry background you will not see the artifacts, but when there is lots of details all over the image the size restriction kicks in and the compression will be high and artifacts appear.

The same "problem" can be seen when browsing images on the back LCD of the K-1, if there is lots of details (for example a landscape scene with leaves and branches all over the screen and everything is in focus) the "blocks" will appear and judging critical focus will be difficult.

Last edited by Gimbal; 09-28-2017 at 06:09 AM.
09-28-2017, 02:25 PM   #27
Site Supporter
Site Supporter
BruceBanner's Avatar

Join Date: Dec 2015
Posts: 5,404
Original Poster
QuoteOriginally posted by Gimbal Quote
Yes that is jpeg artifacts, and I know why you are seeing them.

You are in "browser" mode and are thus looking at the embedded rather heavily compressed jpeg image, not the real rawdata. You can change this in the settings somewhere but not using the jpeg will slow down browsing.

The quality of the embedded jpeg seems to be size restricted (speculation) so when images have less details as in lots of blurry background you will not see the artifacts, but when there is lots of details all over the image the size restriction kicks in and the compression will be high and artifacts appear.

The same "problem" can be seen when browsing images on the back LCD of the K-1, if there is lots of details (for example a landscape scene with leaves and branches all over the screen and everything is in focus) the "blocks" will appear and judging critical focus will be difficult.
I figured it was something like that, I'm guessing that when you open the DNG file in LR or PS you're seeing the RAW, but when using Faststone and CD5 it's showing the jpg? I have noticed for example that the picture you see in Faststone when browsing the DNG file looks vibrant and bright, then you take the same image to LR and it immediately renders far more 'dull', so I always took this to meaning that what you see isn't always what you get, till you open it in proper software.

So can i ask two things;

1) when you say I am in 'browser mode' exactly which program are you referring to? I'm guessing CD5 obviously, but are you also referring to Faststone? It might be handy to force Faststone to showing me the 'real deal' and not the RAW jpgs 'preview' (or whatever) as FS is my first step in making the cull in pictures I take.

2) I shoot RAW, not even RAW+, if I change the JPG options in the camera (K-1), change the JPG quality to 1 star (instead of 3), change the recorded Pixels to XS (instead of Large), does that then apply to the 'jpg preview' in the RAW file? Or are those camera body jpg adjustments only applied when actually setting the camera to take JPGS (such as RAW+ and JPG selected)? I set mine low in an effort to speed things in terms of shooting and giving the K-1 the least amount of things to process as possible.
09-28-2017, 05:08 PM   #28
Senior Member
Jens Lyn IV's Avatar

Join Date: Jan 2014
Location: Ringsted, Denmark
Photos: Albums
Posts: 260
QuoteOriginally posted by Gimbal Quote
I know why you are seeing them.
Mystery solved! Thank you, this was bothering me way more than I expected it to.* I've never noticed artifacts in embedded JPEGs, probably because I only take a cursory glance in Browser mode before switching to Laboratory.

(The relevant setting in DCU5 is Tools - Options - Image Display - Display RAW File in Browser Mode.)

*leekil briefly made me feel like XKCD #386, and that's not healthy...
09-29-2017, 02:19 AM   #29
Pentaxian




Join Date: Apr 2007
Location: Sweden
Posts: 2,106
QuoteOriginally posted by BruceBanner Quote
So can i ask two things;

1) when you say I am in 'browser mode' exactly which program are you referring to? I'm guessing CD5 obviously, but are you also referring to Faststone? It might be handy to force Faststone to showing me the 'real deal' and not the RAW jpgs 'preview' (or whatever) as FS is my first step in making the cull in pictures I take.

2) I shoot RAW, not even RAW+, if I change the JPG options in the camera (K-1), change the JPG quality to 1 star (instead of 3), change the recorded Pixels to XS (instead of Large), does that then apply to the 'jpg preview' in the RAW file? Or are those camera body jpg adjustments only applied when actually setting the camera to take JPGS (such as RAW+ and JPG selected)? I set mine low in an effort to speed things in terms of shooting and giving the K-1 the least amount of things to process as possible.
I was referring to CD5, the "browser" button is lit up / selected in your example image. I don't know anything about Faststone though as I don't use it.

I don't believe the jpeg options as in size and quality affect the embedded image quality, although I don't really know for sure.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
artifacts, description, display, dng, file, geforce, gtx, jpeg, lr, mode, none, nvidia, photography, photoshop, pop, process, update, window
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pixel Shifted Images Rondec Pentax K-1 & K-1 II 1738 03-04-2024 04:33 AM
Pixel Shifted Snoqualie Falls using 24-70mm Pentax AwesomeIan Pentax K-1 & K-1 II 20 07-01-2016 09:32 AM
Sky pixelated - k-5 II Meg4mi Troubleshooting and Beginner Help 9 12-09-2015 12:04 AM
My videos turn out grainy and pixelated. OpticalF Troubleshooting and Beginner Help 3 01-31-2011 06:27 PM
K-x IR Photos Pixelated after PP Perrumpo Troubleshooting and Beginner Help 10 04-18-2010 04:32 PM



All times are GMT -7. The time now is 11:45 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top