resize document

[n.l.83]

hello, 

my name is Nicolas, I am confuse with the Resize Document.

I put my picture on a website to sell them, I have the choice between selling digital files or print. 

Because I want people to get good quality print I resize the pictures at 300dpi, but because I don't understand it really well I don't change the Affinity setting with "resample on" and "bilinear". My camera is a canon 550d 18mp, picture size is about 5184 x 3456px, when I resize to 300dpi I get about 21600 x 14400px which is 311mp. On the website I use I can sell pictures up to 50mp called "Super High Resolution" and by uploading my resize pictures I am able to sell them at 50mp.

Now I would like to know if what I am doing is ok for image quality purposes or should I keep the resample off to stay at 18mp and 300dpi?

and if it is ok should I stay in bilinear or should I change to bicubic?

 

Thank you for your help

[toltec]

Changing the  dpi does not affect the resolution (pixel count) of the file unless you choose resample.

Resample changes the resolution, which is what you want.

 

I suggest you read this. I explained it there

 

https://forum.affinity.serif.com/index.php?/topic/36112-rasterize-resolution-in-designer/

 

and Serif did a video, search for   Affinity Photo - Understanding DPI

 

Normally, use bilinear if downsizing, bicubic if upsizing, but if you are upsizing to sell, try lanczos 3 as the final quality can be better, although it is slower. As for Lanczos 3 Separable or non Separable, it really depends on what the picture content is. Sometimes one is better, sometimes the other. You will need to experiment!

 

If you want to upsize, change the pixel size number until you get about 50 mp. Ignore the dpi.

[n.l.83]

Cool, thank you for your help

 

[Freddie360]

I have and issue with 'Resize Document', I have been using the PS 'Image Size' for years and am confused as to why AP does not automatically calculate and show the reduced mm size when I change the ppi. For example in PS when I have an image at 72ppi and 200x 200mm and key in 300ppi the mm size changes to 48x48mm, as a artist referring to hard copy drawings I find this very useful. If I do the same in AP and change the 72ppi to 300ppi the mm size stays at 200x200ppi. I see that the pixels change, but I need to see the reduced mm size, it may be that 'resizing an image' AP works differently from PS  and I have to learn a new trick, but as yet I cannot find it. See images attached.

[lepr]

.

[Freddie360]

Ownr, I must be missing something in AP Resize as I am not getting what I can get in PS. In AP no matter if Resample is on or off I cannot get the mm sizing to change when I change the ppi as I do in PS. The pixels change but not the mm size, so how does one easily ascertain the physical size of the document. See videos

AP Screen_Recording.mov

PS Screen_Recording.mov

[MEB]

Hi Freddie360,

Currently Affinity doesn't show the corresponding dimensions when Resample is disabled, however here's something you can do to  force it to show the dimensions when you adjust the dpi: set the dpi you want press Enter then tick and untick the Resample box - the greyed out units should update to reflect the new physical dimensions.

[Freddie360]

MEB - thanks, thats a workaround that will do for the present and I hope in the future AP aligns its 'Resize Document' more in keeping with the 'Image Size' in PS. I have been finding that AP sometimes does a thing very differently than I am used to in PS, and I must and will adapt to work differently. However, this is one time where the PS dialog is superior to APs one.

[Pšenda]

I have a document/image with "Pixels" units.

 

Change DPI to 300, and Size recalculate to new pixel value.

 

 

Same document in "Millimetres" units,

 

change DPI, and nothing!