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11-03-2017, 08:58 AM   #1
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new K1 owner wants to know: Up-sizing files in PDCU-5? What algorythm used?

I am using the PDCU-5 that came with my new K-1 (do not have Photoshop or Lightroom) and want to know what algorythm it uses to up-size files. Nearest neighbor (not good), bicubic or better. Does anyone know answer to this??? I want to take an image cropped to about 6600 x 4400 pixels and print it at 24" x 36" without any softening of detail. Thanks to all you helpful forum members...JerryCoyote

11-03-2017, 09:07 AM   #2
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QuoteOriginally posted by JerryCoyote Quote
I am using the PDCU-5 that came with my new K-1 (do not have Photoshop or Lightroom) and want to know what algorythm it uses to up-size files. Nearest neighbor (not good), bicubic or better. Does anyone know answer to this??? I want to take an image cropped to about 6600 x 4400 pixels and print it at 24" x 36" without any softening of detail. Thanks to all you helpful forum members...JerryCoyote

There's something I never bothered thinking about.

I've never heard you can lose detail upscaling, or read on a PP software site what upscaling method was used.

Borisleto always recommends some upscaling software, i memory serves me well. Maybe he'll turn up.
11-03-2017, 09:38 AM   #3
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QuoteOriginally posted by JerryCoyote Quote
I want to take an image cropped to about 6600 x 4400 pixels and print it at 24" x 36" without any softening of detail. Thanks to all you helpful forum members...JerryCoyote
Who is doing the printing? If you, the conventional answer is to simply let the print driver do the work of optimizing rather than do an upsize. If a printing service, you might want to ask their advice.


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11-03-2017, 10:01 AM - 1 Like   #4
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QuoteOriginally posted by stevebrot Quote
Who is doing the printing? If you, the conventional answer is to simply let the print driver do the work of optimizing rather than do an upsize. If a printing service, you might want to ask their advice.


Steve
My printing service suggests upscaling but doesn't care what is used. What you need to upscale is the native resolution of your printer, 300 PPI (Canon) or 360 DPI, HP.

Someone still has to convince me this is an issue.

GIven that we are talking about images reproducing images with measured resolutions of over 3000 lw/ph And you're talking about a 36 inch print, the measured resolution is going to be 83 lines per inch on the print. If you can actually see differences between different upscaling methods at that size, I'd be extremely surprised. I'm guessing these kinds of issues were much more important on lower resolution cameras.

11-03-2017, 10:47 AM   #5
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Don't think any of the replies related to the OP's original question which was what method PDCU-5 software uses for upscaling. The method can definitely impact the quality of the file (nearest neighbor just duplicates pixels) so it would be nice to know. As others have suggested, he might well leave upscaling to the printer which in most cases results in a good upscaling (unless he is doing the printing himself in which case, his printer will upscale unless the need is to send the printer the best upscaled print at its native resolution).
11-03-2017, 11:29 AM   #6
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I cannot answer what method of upsampling PDCU 5 employs so failed at the first hurdle :-). But some of this was covered in this post, so perhaps the question germinated there
New K1 owner wants to print LARGE - PentaxForums.com.

Not to try to teach granny to suck eggs but some information that might be of use

Conventional wisdom on this subject is that if you want to retain optimum IQ then you do not let the printer manage either colour or upsampling.

Dealing with the case of upsampling the reason is damn simple. The printer driver will upsample to its required PPI either 300 or 360 Canon Epson respectively regardless of what you may think you are sending it and therefore what you think it is printing.

Send it an image at any PPI you like for a particular print size and it will upsample or downsample as required to 300 or 360 PPI and produce a proprietary bitmap to send to print. It does this by using nearest neighbour algorithm. Nearest neighbour is the simplest and fastest algorithm but the results are very poor compared to what a dedicated application can achieve including LR and PS.

Photoshop offers 5 methods of resampling:

Nearest Neighbour Basic, and very fast: To create a new pixel the value of the pixel next to it is copied.

Bilinear is more complex and generally produces better quality. Colour or grey values are set according to the colour of each pixel surrounding

Bicubic creates better effects than both the above but takes longer. It looks at surrounding pixel but the calculations is much more complex and intesive and produces smoother tonal gradations.

Bicubic Smoother is a newer interpolation method that has been designed for upsampling giving a smoother result which handles sharpening better than the others. Its alter ego being Bicubic Sharper but this one designed for downsampling and preserving detail better than Bicubic

There is one new method in later versions of PS Preserve detail I am not 100% on this so not covered.

So the question is can you really see the difference between these algorithms in print. The answer being an absolutely, definitely maybe.

We know that Bicubic Smoother will give a better starting point and allow an image to handle subsequent sharpening the best certainly better than Nearest Neighbour which the print driver uses.

But we need to be presenting an image resolving great detail to maximise the benefits. If we then throw in theoretically correct viewing distances then the added quality is likely not to be seen (although it would be there in the print if looking closely)

Quick example viewing distance calculated on 24x36 print = 43" EDIT: This not really correct as the viewing distance is normally 1.5x -2.0x diagonal therefore viewing distance actually around 65"
PPI required for a viewer with 20/20 vision = 80 ppi:. EDIT: Based on the revised viewing distance above PPI needed = 53

Therefore we could easily get away with just sending image data for most DSLR's and get an OK print, but the image data at 80 ppi is going to be upsampled for a Fuji 570 printer by the driver to 300 ppi using nearest neighbour. So why not upsample first to 300 using the superior Bicubic Smoother or better?

Suppose that instead of viewing this print at 43" a photographer calls and wants a look at 12", what pixel density do we now require? The answer would be around 286 ppi our upsampling should score over the printers own for the reasons highlighted.

Last edited by TonyW; 11-03-2017 at 01:24 PM.
11-03-2017, 12:00 PM   #7
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If the subject is stable then you can try using pixel shift. That gives lot more data.

11-03-2017, 12:07 PM   #8
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QuoteOriginally posted by TonyW Quote
I cannot answer what method of upsampling PDCU 5 employs so failed at the first hurdle :-). But some of this was covered in this post, so perhaps the question germinated there
New K1 owner wants to print LARGE - PentaxForums.com.
Same OP, so apparently the suggestions there were inadequate?

QuoteOriginally posted by TonyW Quote
Therefore we could easily get away with just sending image data for most DSLR's and get an OK print, but the image data at 80 ppi is going to be upsampled for a Fuji 570 printer by the driver to 300 ppi using nearest neighbour. So why not upsample first to 300 using the superior Bicubic Smoother or better?
Yes, that makes since. So, applying this to a PDCU-5 workflow from DNG, how would one accomplish this most directly with best quality? I did a quick Google search and the question of upsize from PDCU or Silkypix has been a common topic of discussion on the web for a decade or so.

If it were me, I might simply do the upsize using PDCU-5 and see how well it works using onscreen inspection.


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11-03-2017, 12:32 PM   #9
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The Pentax JPEG engine is not very good for dealing with fine details. You should be able to empirically check what algorithm it uses for scaling. My guess is bicubic sharper. However, I'd recommend using something else for raw conversion to begin if you're after the best image quality. Even if you upscale well, your result will suboptimal if the input is suboptimal

Using pixel shift can certainly mitigate this a bit, but it's not a universal solution.

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11-03-2017, 12:52 PM   #10
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The only really great upsizing software I've seen is PerfectResize, and if you won't spring for Lightroom or something, you're definitely not going to want to spend ~$80 on resizing software (or $150 IIRC for the full OnOne PerfectPhoto suite)
11-03-2017, 12:54 PM   #11
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QuoteOriginally posted by stevebrot Quote
.

Same OP, so apparently the suggestions there were inadequate?
Maybe, but my take is that the question is much more specific aimed at this particular application.

QuoteQuote:
Yes, that makes since. So, applying this to a PDCU-5 workflow from DNG, how would one accomplish this most directly with best quality? I did a quick Google search and the question of upsize from PDCU or Silkypix has been a common topic of discussion on the web for a decade or so.
I have to confess I did look at PDCU briefly as it came with the camera and previously looked at SIlkypix offering from a Nikon user perspective. I consigned it to the trash bin on both occassions as it did not offer anything that I could not accomplish in my existing editing workflow - perhaps a little hasty or harsh but...
So it seems that there is no option to choose upsample method or documentation to show what method employed

QuoteQuote:
If it were me, I might simply do the upsize using PDCU-5 and see how well it works using onscreen inspection.

Steve
The problem for me with this is that the standard monitors just do not have enough resolution (I want at least 300 ppi) to make a valid judgement. Most being around 100 ppi means that viewing an image that needs to be sent to Canon/Fuji/HP and setting a view of 100% equates to a 300% enlargement of the image. When sharpened correctly this image should appear really 'crunchy' to be optimal in print.

If we then decide to view at actual print size in PS we reduce the view to around 33% we now only have 100 screen pixels representing the 300 of the final print - just not enough for fine evaluation and a further problem is the scaling issues at uneven sizes with most image editors. Perhaps a better solution I have seen would be to view the image at 50%, but TBH I just cannot get on with this method either accepting YMMV.

By far the best way is to actual make a print or better yet a section/s at final size and sharpening, easy if you print yourself. Time consuming and expensive if you outsource
11-03-2017, 01:06 PM   #12
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QuoteOriginally posted by Bob 256 Quote
Don't think any of the replies related to the OP's original question
Well, that's an interesting opinion.

QuoteOriginally posted by JerryCoyote Quote
I want to take an image cropped to about 6600 x 4400 pixels and print it at 24" x 36" without any softening of detail.
I guess you didn't read this part of the question.
11-03-2017, 01:08 PM   #13
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Hope adding onto this thread OK. I am just curious about opinions here as the subject about enlargement mentioned reference different programs.

Below is a portion of a small image I had sent to me enlargement of around 41x (if memory serves). What you are looking at is a scan from the prints side by side (shown here at 100% zoom).

Stand away from the screen (or the actual print) and any differences negligible as would be expected.

But assuming it will get viewed closer than 'normal' is there anything to recommend one view over another?
If so which?
And why?

BTW: There is no 'correct' answer as such

Last edited by TonyW; 12-20-2017 at 05:53 AM.
11-03-2017, 02:54 PM   #14
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QuoteOriginally posted by TonyW Quote
Hope adding onto this thread OK. I am just curious about opinions here as the subject about enlargement mentioned reference different programs.

Below is a portion of a small image I had sent to me enlargement of around 41x (if memory serves). What you are looking at is a scan from the prints side by side (shown here at 100% zoom).

Stand away from the screen (or the actual print) and any differences negligible as would be expected.

But assuming it will get viewed closer than 'normal' is there anything to recommend one view over another?
If so which?
And why?

BTW: There is no 'correct' answer as such
Left is pixellated, right is soft.
11-03-2017, 04:10 PM   #15
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QuoteOriginally posted by TonyW Quote
Hope adding onto this thread OK. I am just curious about opinions here as the subject about enlargement mentioned reference different programs.

Below is a portion of a small image I had sent to me enlargement of around 41x (if memory serves). What you are looking at is a scan from the prints side by side (shown here at 100% zoom).

Stand away from the screen (or the actual print) and any differences negligible as would be expected.

But assuming it will get viewed closer than 'normal' is there anything to recommend one view over another?
If so which?
And why?

BTW: There is no 'correct' answer as such
Are the "jaggies" present on the left-side print or are they scan artifact?

Steve
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