Advice Please - Pixel Interpolation in PDCU?


McGregNi

Link Posted 24/11/2012 - 19:37
I have a technical query, something a bit outside my knowledge. I'm just finishing a 'mini guide' to the Pentax Camera Utility software, which I hope people will find helpful here. I'm not trying to cover absolutely every aspect of the programme, but I have tried to offer helpful advice for setting it up.

In the options dialogue there is an 'Image Display' tab, and three choices for 'Pixel Interpolation' which are Nearest Neighbor, Bilinear & Real Zoom.

I'm aware of the Bilinear option in Photoshop when resising or resampling images, but I am unsure of their significance in an editing program for the Image Display? The default is Nearest Neighbour - what would determine anyones choice for one of the others? Any info much appreciated, and of course acknowledged in my Mini Guide!!
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver

johnriley

Link Posted 24/11/2012 - 19:55
Nearest neighbour samples left and right only and is only suitable for diagrams in presentations. Block graphs and the like.

Bilinear samples up and down as well as right and left, but is still pretty basic.

I presume Real Zoom is the same as bicubic, which samples diagonally as well and is the one of coice for photographic images.

That's a very simplified explanation but gets the idea across.
Best regards, John

McGregNi

Link Posted 24/11/2012 - 20:34
John, that good enough for me! If you're happy I shall mention your post in the Guide text and suggest users try 'Real Zoom'. I have noticed that in PDCU4 the large preview does update in a somewhat blocky way, sort of left to right, so maybe the Nearest Neigbour setting is causing this. I'll try the others out and see if it changes anything.

I just wanted something intelligent to advise about this setting in my mini guide!
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver

duncanM

Link Posted 24/11/2012 - 22:05
McGregNi wrote:
..I'm just finishing a 'mini guide' to the Pentax Camera Utility software, which I hope people will find helpful here...

Sounds good- looking forward to it. Such a guide would be greatly appreciated by me at least. It would be very convenient loaded on a second laptop and so able to be consulted rather than having to search the 'help' section in course of using the PDCU application.

McGregNi

Link Posted 24/11/2012 - 22:37
Unfortunately there's not much 'help' in the 'help' of PDCU It just describes the various sliders in very basic terms, with a miniumum of background appliable information. So I saw a gap there! A few people on here and the US forum have mentioned a need for more detailed info and guidance.

You won't have to wait long - I'm just working on the formatting, and getting some feedback and further suggestions first. Watch this space!
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver

duncanM

Link Posted 24/11/2012 - 23:14
McGregNi wrote:
..there's not much 'help' in the 'help' of PDCU

I certainly find it rather unsatisfactory- may your endeavours be rewarded in Heaven..will you be looking for some of that down here too?

McGregNi

Link Posted 25/11/2012 - 00:42
If you feel it might increase my chances of going to Heaven then I'd settle for that.
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver

Joe S

Link Posted 25/11/2012 - 10:02
Not that I want to discourage you, but isn't Pentax phasing PDCU out in favour of Silkypix? I believe every camera now comes with Silkypix instead of PDCU and I would expect most users of K5 and older cameras are rather settled in which program they use.

I could be wrong in all this, though, since I haven't bought anything lately. PDCU and me never got along ...
Hi. My name is Joel and I'm a travelholic.
Stolen kit: Pentax K7 #3428965 and Pentax FA 43mm #0028350

duncanM

Link Posted 25/11/2012 - 11:28
Joe S wrote:
..isn't Pentax phasing PDCU out in favour of Silkypix?

PDCU = Pentax Digital Camera Utility, currently and for several years past provided by Pentax with their cameras. It has always been described as 'a portion of SILKYPIX Image Processing Engine, and is a limited version of the highly regarded full strength Silkypix engine, i.e. stripped of some of the 'bells & whistles' of the reputedly excellent (and expensive) full version.
Last Edited by duncanM on 25/11/2012 - 11:29

Algernon

Link Posted 25/11/2012 - 13:35
The version supplied with the Samsung GX-20 was supposed to be the
full Silkypix, but probably only accepeted Samsung files.

-
Half Man... Half Pentax ... Half Cucumber

Pentax K-1 + K-5 and some other stuff

Algi

PeterKR

Link Posted 25/11/2012 - 14:14
Joe S wrote:
Not that I want to discourage you, but isn't Pentax phasing PDCU out in favour of Silkypix? I believe every camera now comes with Silkypix instead of PDCU and I would expect most users of K5 and older cameras are rather settled in which program they use.

I could be wrong in all this, though, since I haven't bought anything lately. PDCU and me never got along ...

"PDCU and me never got along .."

That is exactly how I felt and why I posted a thread looking for any tutorials.

Fortunately, Nigel has taken up the challenge (using me as a guinea pig to test his guide) and I am now a convert !

Once you get into it (and that was the problem) it is actually quite easy to use and at the same time very powerful.
For general use it does all you need to get the best out of your RAW files and no other program may be needed ?

Watch out for the 'Guide' and then give it a try !

Peter

McGregNi

Link Posted 25/11/2012 - 15:49
I think it has been a common practice to refer to the Pentax Utility programme as 'Silkypix', which is not strictly accurate. There is some branding in PDCU which says 'Powered by Silkypix', but the two programmes are many miles apart.

I'm assuming that PDCU as it is will continue and be updated as it has been recently - I saw the latest update report on the Pentax mainsite and it mentions specific new support for features in the new K5II models. However, there have been numerous forum comments concerning installation issues, and people ending up back with version 4.35. If any new K5II owners have a new disc maybe they could run it and see what the new features are. 's' model owners presumably would expect something to remove any moire problems if required. Apart from this there are some new lenses to add in to the database.

Just issuing a copy of Silkypix Developer Studio itself (or a basic version of it) wouldn't actually cover all the bases - PDCU is designed specifically to duplicate all of the Pentax in-camera edit features, such as the shadow / highlight & lens corrections accessed via the LCD control panel, as well as the full Custom Image Parameters accessed via the right hand button on the 4-way controller. Silkypix doesn't have any of these Pentax specific features.

This is one key benefit that PDCU retains over anything else - that you can gain full software control over all of the editing features that the cameras provide, and so save yourself time when shooting not having to fiddle around with all the settings on the camera.

I'll be launching my guide into a new thread soon, hopefully to be of interest to those who have tried out PDCU before and given up or those new to RAW editing who may not yet have any other software.
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver

PeterKR

Link Posted 25/11/2012 - 23:18
The latest version of PDCU4 is 4.40. You need to go to the Pentax Japan website to download it and whilst is is referred to on the English language page hitting the 'DOWNLOAD' button there gives you version 4.35 !!

However, if you change the language to the Japanese page and, ignoring the writing you won't understand (unless you speak Japanese !), just scroll down as if it were the English page and hit the LEFT button it will download an ENGLISH version of PDCU 4.40 (which is 1 byte bigger than 4.35 !)

I did this today, it installed perfectly and I've just uploaded a RAW file converted using it to the gallery.

Incidentally, my files are from a K-r.

Peter

Mandrake

Link Posted 26/11/2012 - 15:00
johnriley wrote:
Nearest neighbour samples left and right only and is only suitable for diagrams in presentations. Block graphs and the like.

Bilinear samples up and down as well as right and left, but is still pretty basic.

I presume Real Zoom is the same as bicubic, which samples diagonally as well and is the one of coice for photographic images.

That's a very simplified explanation but gets the idea across.

It's also not quite accurate! I (having worked on coding image processing software in the past) would describe them as:

Nearest neighbour: Each output pixel in the resized image is the same as the nearest equivalent pixel in the original size image.

Bilinear: Each output pixel is based on a weighted average of 4 pixels in the original image.

Real Zoom: Could be anything really! Certainly it should be using something more complicated than bilinear interpolation based on more of the original pixels - there are many algorithms out there: see http://en.wikipedia.org/wiki/Image_scaling for starters.

That said, assuming it is really bicubic interpolation is not unreasonable - bicubic interpolation uses a more complicated mathematical function to produce each output pixel from 16 pixels in the original image.
Simon

My online scrapbook: http://smxc.co.uk

johnriley

Link Posted 26/11/2012 - 15:09
Thanks Simon, but not quite accurate maybe is accurate enough to understand what's basically going on.

The trouble is that the more accurate some exaplanations becomes the more complex the information becomes, and eventually we lose the audience as their eyes glaze over.

But I'm not disagreeing with you, and appreciate the improvement in the explanation.
Best regards, John
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