Extrapolation: is the printer driver the same or better at enlargements?
I’ve seen this all over the web:
“Don’t bother with fancy and expensive extrapolation software. Just let the printer driver do the enlargement. It’s just as good, if not better.”
Overly optimistic, I’d say… but you tell me.
Below is the same image extrapolated to 300% of the original size.
On the left is the work of PhotoZoom Pro v6, and on the right is the Epson 9890 driver. The results seem pretty clear to me.
also see: https://www.valleau.art/blog/?p=37
Addendum: The original post stopped with the image, above. Then I was asked why I didn’t post my methodology for creating the comparison. Here’s my reply:
As to my blog article, there are the comparison images and no methodology description for one reason: there is only one way to have the printer enlarge an image: pass in the image and choose the resulting size. There are no options, (ie sharpening in the driver) at least with the Epson driver on a Mac.
As to the actual details of the sample image, it’s about 1″ on a side at 360 ppi. (420 x 360 actually.) I passed it in to the printer driver and told it to print it at 300%. That’s the same thing as passing it in at 120 ppi (and in fact, that’s what the driver shows as soon as you put in “300%”)
As to the left hand image, enlarged by PhotoZoom Pro, it’s the same image file, of course, and enlarged to the same amount. In PZP, I set all the controls to Zero except sharpening, which I habitually keep at 41. I set the DPI at 360.
I printed each file (at this point 3.5 x 3 inches), and then scanned them side by side, in a single pass at 600 ppi, loaded the image into Preview, and took a screenshot, and posted the result. (That’s what you’re seeing above.)
So…since there is only one way to enlarge with the printer driver, and that does not allow any post-sharpening because it’s a print by then, I didn’t mention how to do it.
And since using a third-party tool does allow modest adjustment after resizing, and that is the whole point of the comparison, I didn’t mention that either.
I will say that my PZP setting (41) is NOT my final choice for my own prints. It’s an intermediary step that is sort of the equivalent of raw-presharpening – it just brings the extrapolated image back to a fundamental working state. I typically return the image to Photoshop for additional work and sharpening after it’s been resized.