Help with final workflow steps on 2 year Mediterranean map project

[billbane]

I and a cartographer friend have built a map of the Med starting with high resolution satellite image data for land areas (using color gradients for elevations, etc) and bathy depth data for seas to construct a 7200 x 4000 x 72ppi image. The file is huge and includes many, many layers (rivers, lakes, waves, dunes, "monsters", "routes", some raster & some vector), directly and via many linked smart objects.

My question to you experts is how to complete the workflow for printing, especially since this is NOT a photograph, if that latter point makes a difference.

Specifically:

1. The image will be upscaled/downscaled to 21,600 x 12000 x 360ppi. Right now, using Photoshop CC, but is, for example, Perfect resize better? How best to do this?

2. Should I use Topaz details and/or ACR's "clarity" for final contrast improvement? I realize this is a question of taste, but wonder if the upscaling/downscaling generally demand certain corrective actions?

3. I might print to metal (Bay) and might print to paper. Is NIC's output sharpener necessary/optional, at which settings, or should some other approach be used? The question again relates to the large upscalling/downscaling of other than photographic pixels, but also to metal vs paper?

I think this is not a mainstream Luminous Landscape question type but am hoping (and expecting) that the experts here can help me with this very-important-to-me project.

Thank you in advance.

Bill Bane

[David Sutton]

Hello Bill. No-one has replied so I'll have a go.
Just to re-cap. You have a 7200x4000 pixel image. The ppi is not useful as it depends on your screen size and zoom amount.
You are duplicating, flattening and resizing it 300% to 21,000x12000. Again, the ppi is irrelevant.
You are going to print on an Epson printer (Canon calls for a 300/600 ppi file). Now the ppi is useful. At 360 ppi you'll end up with a 58.33 x 33.33 inch print, if my math is correct. That's what you want? Then I agree about the re-sizing. The original file would only give 121 ppi for a 58.33 x 33.33 inch print, and I doubt that would be enough.
I'd prefer Perfect Resize to Photoshop. Some folks recommend PhotoZoom. I doubt there is a huge difference between them once you print and stand back. If your viewers are going to stand close, then maybe print an A4 section of the file and see which uprez software you prefer.
If you are going to sharpen I'd do it after uprezzing to avoid artefacts. If you are using Topaz Detail on a separate layer, try pasting part of the image on an A4 sheet of paper (to save on printing), slightly over-sharpen and then mask the layer with a gradient on the mask. The print will have no sharpening on one side and too much on the other. Pick the spot you like and select that value on the mask.
Can't help with Nik output sharpening. I print out of Lightroom or Qimage, and both sharpen fine.
David

[Pictus]

1- To upsize try Reshade(free/Windows only) http://reshade.com it is good for illustrations/maps.

2- Yes can use.

3- Different media/size needs different amount of output sharpening.
 

[billbane]

David,

I have the math on upscaling down ok.

Your suggestion of using a gradient looks useful and I will try it. 

My understanding is that one always does preprint sharpening because of printing technology issues and NOT the characteristics of the pixels (eg. photo pixels vs gradient driven pixels). Is that correct?

My printer is an Epson P800, but I will eventually need an outside printer because the top dimension will be 60 inches.

Thanks!
Bill Bane

[billbane]

Pictus,

Thanks for the help.

I will try reshade. It looks interesting.

Regarding metal printing, I called Bay and the customer support folks like I was from Mars when I asked them about sharpening. I have goggled this issue and found nothing.

I think this leaves me with "trial and error". Even if I do print segments, aka snips, I will end up with a good bit of shooting in the dark. Maybe that path is my only option, but I was hoping someone might had some experience.

Thanks again.

Bill Bane

[David Sutton]

My understanding is that one always does preprint sharpening because of printing technology issues and NOT the characteristics of the pixels (eg. photo pixels vs gradient driven pixels). Is that correct?

Thanks!
Bill Bane

Aesthetic considerations aside, output sharpening is to compensate for dot gain. I let my printing software take care of it.
If you are doing your own output sharpening and have not done this before, I would take an A4 segment of the file, over-do the output sharpening and use a gradient to decide the amount as per my earlier post.
Same thing for the amount of saturation, contrast etc etc for critical subject matter.
If you are sending the file out for printing I think preprint sharpening is the least of your worries and wouldn't worry about it. Getting a good colour match and shadow detail is often "interesting".
David

[Bart_van_der_Wolf]

I and a cartographer friend have built a map of the Med starting with high resolution satellite image data for land areas (using color gradients for elevations, etc) and bathy depth data for seas to construct a 7200 x 4000 x 72ppi image. The file is huge and includes many, many layers (rivers, lakes, waves, dunes, "monsters", "routes", some raster & some vector), directly and via many linked smart objects.

My question to you experts is how to complete the workflow for printing, especially since this is NOT a photograph, if that latter point makes a difference.

Hi Bill,

The mixed vector/raster layered nature of your image makes it a bit harder to recommend one particular path forward. Luckily, your resampling requirement of 300% is not too extreme. Perfect Resize, or especially PhotoZoom Pro(!), can both make very good upsamples of that kind of image (a small crop, say 300x300px, of what we're talking about might help with tuning some settings).

Topaz Detail may be helpful before, but also after resampling, because it can accentuate detail without risk of creating halos, and reduce the upsampling blur. It's also useful for tuning the output sharpening to a specific output medium.

Cheers,
Bart

[billbane]

Bart,

Attached is a generally representative snip showing different land elevations with their associated colors. There is a bit of the seas (which is a separate layer) which I add since one of the keys is the quality of the shoreline.

I have quite a few vector layers (not shown). My assumption is that I could/should upsize them separately as that would reduce the "confusion" of the upsizing/sharpening algorithms.

My friend and I are not finished. There is still work on saturation and contrast before upsizing.

If you also have any suggestions what to do/not do before sending to a metal printing, they would be most welcome.

Thank you very much!!

Bill

PS. I have read and enjoyed, and sometimes understood, your many useful posts in this space. Thanks for that too.

[billbane]

Bart,

I tried to upload the file as a tiff but it failed and said contact the forum administrator. I had tried but failed to find a FAQ about file uploading. When I switched to Jpg it worked.

However, when the file is in jpg, this image, particularly the greens, become noticeably more saturated. I have seen this in file exchanges with my friend. Do you know if this is this "normal"?

Bill