Affinity Resolution of Photos

[msbfrnj]

Hi Everyone.  So I am a Merch by Amazon participant.  Their instructions for submitting images for their products are 300 dpi and 4500x5400 for PNG images.

Soooooo, I am wondering, is it ok to see pixelation on a png file at the 400 zoom level for 300 dpi in Affinity products?  I know I can use a svg if I want no pixelation, but svg's don't work if you have any type of nice gradient on your image.  (I know you know all this  ).  So is the point that those POD houses don't worry about pixelation because 300 dpi is enough?

Also, trying to create 300 dpi resolution in Affinity Photo or Affinity Designer doesn't help the look of the image resolution.  OR do I have to save the file at the 300 resolution first to see the difference.  So confused.

Thank you for helping a "newbie who knows just enough to be dangerous" - which means I might not  know too much!    Thanks for any and all help and explanations to help clear this up.  Brenda

[GarryP]

Are you starting with images, which you are then manipulating, or are you creating the images from scratch?

If you can give us an idea of the process you are following we will have a better idea of how to help.

If you are starting with images then it might help us to help you if we can see one, or preferably more, of the images you are starting with.

Once we have some idea of what you have we should be able to come up with a way of getting what you want.

The forum software has a habit of manipulating images that are uploaded directly so, to show us the images, ZIP them first, and then upload the ZIP to the forum. That way we can see the images exactly as you see them.

[Alfred]

5 hours ago, msbfrnj said:

I am wondering, is it ok to see pixelation on a png file at the 400 zoom level for 300 dpi in Affinity products?

Why are you inspecting it at 400% zoom? A print resolution of 300 PPI is perfectly adequate for general colour printing: you would only need more than that for a high-end ‘coffee table’ book, or for something like a map that you might inspect with a magnifying glass.

At 300 DPI, the print size of your 4500 px × 5400 px image is going to be 15″ × 18″. No one is normally going to view an image of that size from close enough to notice any pixelation.

[thomaso]

7 hours ago, msbfrnj said:

is it ok to see pixelation on a png file at the 400 zoom level for 300 dpi in Affinity products? 

Yes. At this zoom level it can be expected to see pixelation, in Affinity or any other raster image viewing app and regardless of the file type (JPG, PNG, PDF, …).

It matters how the zoom level is defined in the viewing app: Its 100% zoom may refer to 100% of the number of pixels (and show every single pixel of the image file) – or to 100% of the physical output dimension. The Affinity apps differ between "Pixel Size" and "Actual Size" (or "Print size" in the macOS Preview app while Acrobat offers a preference setting for its displayed pixel / inch). In Affinity also the currently selected document unit (px versus in or mm) may influence the displayed physical size on screen at its "100%" view option, varying with the monitor's hardware pixel size and density (and the resolution set for the computer's graphic card).

1 hour ago, Alfred said:

Why are you inspecting it at 400% zoom?

If 100% correspond with the physical output size, then a zoom level above 100% can give an impression of the visible image details in a 300 dpi layout and print result: On a monitor with 72 dpi the zoom level of 400% corresponds roughly with the 300 dpi (ppi) on physical output: 4 x 72 = 288.

If a zoom level of 100% means to display the image on screen in the physical print size it might not show all details (= every pixel) of the image, for instance fine lines in a fence, tiny text on a sign or single hairs in a portrait because it "compresses" the image visually to match the output size according to the layout document resolution and thus "suppressing" pixels from being displayed.

Accordingly a 400% zoom level may show every single pixel available in a 300 dpi document but at a 4x larger physical size on screen.

2 hours ago, Alfred said:

A print resolution of 300 PPI is perfectly adequate for general colour printing: you would only need more than that for a high-end ‘coffee table’ book, or for something like a map that you might inspect with a magnifying glass.

300 dpi (ppi) corresponds about with the resolution of the human eye at 'normal' reading distance (e.g. a book). The visibility of single print / ink dots when viewing a postcard for instance is also influenced by the print grid (raster): Increasing the image + document resolution (= its available number of pixels) does not necessarily increase the amount of visible details in a print. If the printing raster/grid limits the minimal size of visible details, a magnifying glass might show single print grid or ink dots but not necessarily more details of the image.

For the same reason increasing the hardware pixel resolution of a monitor screen above ~300 ppi would not lead to more details for human eyes. Thus a smart phone or watch does not have or need a screen resolution with more than ~300 dpi (~10 px per mm = 0.1 mm/px) while a digital billboard may have a hardware pixel size of several mm, where, as you mentioned already, the viewing distance matters, too.

[msbfrnj]

Hi, Thanks so much for the replies.  The image below is 300 dpi and 4500x5400 according to Irfanview.  It pixelates at 100% on zoom on A.D.  I tried to zip the Owl Screenshot to you but kept getting a #200 error.

So, I guess I was trying by sight to prove that these files that say 300 dpi are going to be sharp by using the program's zoom option.  Files made from scratch hold up nicely with the zoom option at 400% - there is not pixelation.  (A.D or A.P.)
To answer one other question.  I am getting a lot of these pics from online at different public domain sites or chat gpt is spitting them out.
They are all low resolution files.  AND so many of the apps that are online now that are for Enhancing and Upscaling don't necessarily say what dpi these files are changed to.  Sooooooo, I was using the zoom option to try to see what in the world dpi am I looking at per the zoom tool.

Merch just says 300 dpi and so someone is saying here that 300 dpi doesn't need to be crystal clear like I was expecting, for the POD printing houses.  

So like for instance, if I take like a 96 dpi graphic at like 1200x1200 and put it into AP and change the dpi to 300, it doesn't really LOOK any different.  Am I supposed to take for face value that the file is really 300 dpi and I just don't see it from the zoom level - because I do see that a 300 dpi graphic made from scratch does achieve that crisp clear graphic/text at 400 zoom level?

Hope I'm making sense.  Would really like to understand a little more about AD&AP when it comes to things like this.  Couldn't find anything comprehensive.

Thanks so much
Brenda

 

 

 

 

 

 

 

abstract-owl-bird-art-PRE 1695191440PTJ - iheartimg upscaler).zip

[Alfred]

Images on a computer screen are simply made up of pixels (picture elements). A 1200 px × 1200 px image @ 300 DPI will look exactly the same on screen as a 1200 px × 1200 px image @ 96 DPI: the DPI setting only comes into play for physical output, where at 300 DPI you’ll get a 4″ square and at 96 DPI you’ll get a 12.5″ square.

[thomaso]

3 hours ago, msbfrnj said:

The image below is 300 dpi and 4500x5400 according to Irfanview.  It pixelates at 100% on zoom on A.D. 

This file [named "… upscaler).jpg"] has been upscaled by far more than 200% and additionally got sharpened, causing the artefacts for this initially smooth vector illustration. When used with 300 dpi you can't avoid its pixelated look. – If you can't get the image in the required size and need to use an upscaled version you might not sharpen at all, or sharpen quite subtle and in 100% pixel view only. Alternatively you might try a software that is specialized for upscaling.

[msbfrnj]

OK...I understand (I think). But basically, when I see that the graphic info output says 300 dpi at whatever size, take it for face value.  It's good enough for the POD printers?

I wish I could just use the programs I have from Affinity for upscaling to 300.  Can that be done or not?  Again, the photos I am usually using are low resolution - like 1024x1024 from Chat GPT.

One last question - can you tell me how I would enlarge photos to a very high resolution for like Displate?  Does AP do that?

Thanks so much
Brenda  

[RichardMH]

AP has Resize Document in the Document menu. Its old school, non AI. You probably need to experiment with the Resample options to see what suits.

Topaz Gigapixel AI is good. Might be worth running the free trial. Gigapixel at 4X and 400%.

[thomaso]

13 minutes ago, msbfrnj said:

But basically, when I see that the graphic info output says 300 dpi at whatever size, take it for face value. 

Don't. As your owl example shows the 300 dpi don't say anything about the image quality. When placed in an Affinity layout you could increase the placed DPI to achieve better quality but then it also will get downscaled in the layout. – And, as Alfred mentioned already, the DPI in a saved raster image file (jpg, png, tiff, …) is not related to its number of pixels. You can save an image of 1000 pixels with 1 dpi or with 300 dpi without changing the image content. The DPI saved in some in images gets relevant only if placed in a layout app like Affinity, then the image's DPI influences its placed dimension in the layout. You can save an image without setting a certain DPI for this image without influencing the image quality, accordingly you can change the DPI of an image without changing its pixels.

20 minutes ago, msbfrnj said:

It's good enough for the POD printers?

300 dpi is the fully sufficient standard resolution for prints of books, magazines etc., assuming an according image quality. For your upscaled image a required resolution within a 300 dpi print layout might be 600 or 800 dpi (to reduce the artefact appearance) and thus in an accordingly smaller size (50 – 25%).

28 minutes ago, msbfrnj said:

I wish I could just use the programs I have from Affinity for upscaling to 300.  Can that be done or not?
(…) 1024 x 1024

APhoto has two extra upscaling options. Try, what you get with those (the result depends on the image type, e.g. details/contrast vs. gradients).

For upscaling always the dimensions of two objects matter: the size of the start object + the size of the desired object, in a physical, absolute unit. A resolution is not a size, a question like "can the app upscale to 300 dpi" doesn't sound useful (yes, it can). Also, a Pixel has no absolute size – different to a Millimetre, an Inch, a Litre, mph or kWh etc.

Very rough: an image with 1000 px can be printed in about 3 inch (or ~10 cm).

35 minutes ago, msbfrnj said:

One last question - can you tell me how I would enlarge photos to a very high resolution for like Displate?  Does AP do that?

A certain print technology or the brand "Displate" is not relevant in this case – but, again, the size does matter.

While Affinity can upscale to any resolution, its results may feel not satisfying compared to the various available apps that are specialised for upscaling. Try an internet search for apps and example images or just try "GigaPixelAI" for instance.

In particular for raster images initially created with vector you alternatively might try a vectorizing app. Those "convert" pixels to vector and thus enable you to upscale quite lossless.