Crop tool image sizing

[CedarHouse]

Trying out Affinity Photo Beta version 414 for Windows 10. Opened a RAW image in Develop and then click Develop button to go into Photo Personae. Image comes in at 4928px by 3264px and DPI 96. Crop Tool also displays same in Unconstrained and Absolute Size as well as in the Document Size. Cancel Crop Tool and then change Document Size to DPI 300 with Resample tick removed. Come back with Crop Tool and Unconstrained now shows 4928px by 3265px with DPI of 300. Go to the Absolute size button and the Image is 4928px by 3265px but the DPI is 96. In Absolute size the DPI does not change even though the Document size has been changed to 300DPI.

[DarkClown]

DPI does not change the document size. It's a unit to describe the printing resolution.
https://en.wikipedia.org/wiki/Dots_per_inch

Despite the fact that everybody talks about dpi it's actually completely meaningless unless you have a printer and need to define the amount of pixel per inch (PRINTING size of your document). Within any kind of SW ist's jus a random number that is of absolutly NO interest until you need to print your work. It will not change pixel-size of a document. There is no resampling done when you change dpi (actually there's absolutely NOTHING done when you change dpi in your software).

[CedarHouse]

I am fully aware of the actions of DPI (ppi). In my particular case I am editing images for printing. I rarely use my images for display where the DPI (ppi) makes no difference as to how and image is displayed by a monitor or digital projector or other display devices. All my images are prepared on the basis that at they will be printed onto a paper medium, mostly on to paper at 16 inch by 12 inch or onto A3 paper but the image would be a specific size on the relevant paper.

The particular and peculiar issue I have is with the Crop Tool change from version 1.6 to version1.7. My image comes into Photo Personae at 4928px by 3264px say set to 300 DPI in Document Resize as previous post. Unconstrained mode bar shows 4928px by 3264px and DPI of 300 and the crop grid is to the edges of the image.  Resize image in Unconstrained to 3000px by 3000px and crop grid boundary displays as I would like it but not clicking the Apply button at this stage. Click on Absolute size and the crop grid boundary changes to a rectangular image smaller in size than the original image but the bar still shows 4928px by 3264px with DPI 300. Click back to Unconstrained and the size in the bar is 3000px by 1987px. Which is not the 3000px by 3000px (1 to 1 ratio) I started with but is now the ratio of 77 by 51. I would like to check the size of image in either millimetres or inches as in the Absolute size the alternative unit sizes are available, whereas in Unconstrained mode the units are not available. So far I cannot get the Absolute size to match the Unconstrained size. The only way is to to use the Absolute size and first adjust the height and then Apply the crop. Then open the crop tool a second time and now apply the width dimension I require. This makes the crop boundary exceed the image boundary particularly in 1:1 ratio. so then one needs to drag the crop boundary back to the image boundary with the grab points on the crop boundary top and bottom then click Apply to get a correctly sized image for print reproduction. The image is copy and pasted onto a canvas at either 16 inch by 12 inch or A3 with the image to specific size to suit the paper size medium being used.

[Petar Petrenko]

On 7/9/2019 at 2:22 PM, DarkClown said:

DPI does not change the document size. It's a unit to describe the printing resolution.
https://en.wikipedia.org/wiki/Dots_per_inch

Despite the fact that everybody talks about dpi it's actually completely meaningless unless you have a printer and need to define the amount of pixel per inch (PRINTING size of your document). Within any kind of SW ist's jus a random number that is of absolutly NO interest until you need to print your work. It will not change pixel-size of a document. There is no resampling done when you change dpi (actually there's absolutely NOTHING done when you change dpi in your software).

Yes, I agree.

The real image resolution is its size (W x H) and DPI just inform us how many pixels are used per measurement unit for printing.