Print Options & image interpolation

[gennadiy]

Are my assumptions correct:

When printing:

1. Interpolation occurs when the scale (Zoom Size) is not equal to 100%.
2. Interpolation does not occur when the print Position (x, y) or Alignment changes.
3. Interpolation occurs when the Print Rotated or Print Mirrored option is set..

[russellcottrell]

Interpolation should not occur when rotating 90 degrees or mirroring.

[Martin Huber]

Are my assumptions correct:

When printing:

1. Interpolation occurs when the scale (Zoom Size) is not equal to 100%.
2. Interpolation does not occur when the print Position (x, y) or Alignment changes.
3. Interpolation occurs when the Print Rotated or Print Mirrored option is set..

This cannot be answered so easily. It depends on your OS, on the printer (driver) and on the document you are printing.

"Rotated" is usually handled by the printer driver. On macOS "Mirrored" is handled by the OS.
Simple images in picture mode are output unchanged. The zoom factor doesn't really matter.
For complex documents or in document mode, PhotoLine renders an image at the printer resolution, so interpolation can always occur.

It's probably easiest to use a PDF printer driver and check the resulting PDF document.

Martin

[russellcottrell]

The zoom factor doesn't really matter.

I don't understand that. There would be a big difference between resizing and carefully sharpening an image at the print resolution so it can be printed at 100%, vs. just letting the app or the OS resize it by changing the zoom factor.

[Martin Huber]

I don't understand that. There would be a big difference between resizing and carefully sharpening an image at the print resolution so it can be printed at 100%, vs. just letting the app or the OS resize it by changing the zoom factor.

If the image is a simple one, PhotoLine itself does no scaling. It just tells the printer driver where and how large to print the image. The scaling is done by the printer (driver).

Martin

[russellcottrell]

Well, then, speaking of the entire process from image file to ink on paper:
- First, decide how large you want the printed image to be.
- Then, decide how many pixels you will need. This is based on how many pixels per inch the printer wants. For example, my Canon printer driver wants either 300 or 600 ppi. (Note that this is not the same as dots per inch; the Canon uses 2400x1200 dpi; many dots are used to print one pixel).
- Resize the image using all the tricks at your disposal (such as Mitchell-Netravali interpolation followed by halo-free L-channel sharpening, for example), so that it has the right number of pixels for its printed size (an 8x10 print at 300ppi would need to be 2400x3000 pixels, for example). YOU need to do that; don't let the app or the printer driver do it on its own.
- (Save the master image file. If you then want to print it at a different size or resolution, you need to resize and sharpen it again.)
- Now, when you send your beautiful rasterized pixel data to the printer, tell it to print at 100%. Rotating it by multiples of 90 degrees, or mirroring it, or moving it around on the paper will not change the pixel data, so there should be no interpolation at any point (PhotoLine or printer driver).

[gennadiy]

If the image is a simple one, PhotoLine itself does no scaling. It just tells the printer driver where and how large to print the image. The svaling is done by the print (driver).
Martin

Question.
If I change the print start position in the Print Options, PL will add up the missing blank pixels before sending it to the printer.
The image itself is not recalculated.

[bruce1951]

FWIW whenever I need some 'serious' printing I use QImage. [urlhttps://www.ddisoftware.com/qimage-u/][/url]

While Photoline is an excellent piece of software I find that a specialist piece of software is vital for my printing needs. You can set up a 'job' and save it with all your profiles etc and use it over and over getting the same results every time. You can save ink, paper, printer etc etc profiles and QImage will use them. QImage will arrange/optimize prints on a single piece of paper etc etc etc.

[russellcottrell]

Question.
If I change the print start position in the Print Options, PL will add up the missing blank pixels before sending it to the printer.
The image itself is not recalculated.

The print position should just tell the driver where to orient the print on the page; there should be no extra pixels involved.

I almost mentioned QImage. I tried it out; if I did "complicated" multi-image jobs on a regular basis, it might be worth it; but as it is it does not do anything that I can already do with just resizing/sharpening and the printer driver.

[gennadiy]

I almost mentioned QImage. I tried it out; if I did "complicated" multi-image jobs on a regular basis, it might be worth it; but as it is it does not do anything that I can already do with just resizing/sharpening and the printer driver.

Yes, this is not for printing one sheet per week)

[gennadiy]

The print position should just tell the driver where to orient the print on the page; there should be no extra pixels involved.

I don't know how he does it.
My Epson places start position as it is configured,
so the placement of the image on the sheet within the margins can be controlled from PL.

[bruce1951]

QImage does way more than just 'complicated' multi image prints. It manages ink, paper, printer etc etc profiles. Soft proof and editing are also features. Paper and image sizes can be automatically handled.

I use PL for 'simple' prints. Family and holiday prints etc. But for 'advanced' printing I always use QImage. I had a museum that, over a few years, I provided over 600 A3+ and A4 mounted prints. The prints had to be colour correct and consistent. And of the highest quality. (Short of using a pro printing firm). I would never 'trust' or rely on a 'basic' printing procedure that comes with PL.

The key is the 'importance' of your printed output. If it's key then use a specialist program. If not then the likes of PL is fine.

I have no connection with QImage. My copy is actually a few years behind the latest version. But I do know from experience that the output from PL can't match the likes of QImage.