07-27-2021, 12:43 PM
(This post was last modified: 07-27-2021, 12:45 PM by rich2005.
Edit Reason: typo
)
Remember Gimp works in pixels. Did you read Ofnuts post on printing sizes ?
When you know the image size in pixels is correct but the ppi is maybe a default value retained from importing, then change the Print Size ppi value There is no loss in quality, it is an internal setting used by the printer.
Scaling up or down involves interpolation, some pixels are thrown away (scaling down) or pixels are guessed (scaling up) and this results in some loss in quality Might be a lot / might be small.
How this fits in with the scale dialogue. Remember again Gimp works in pixels. Keep your eye on the size in pixels
1) The original image, 1440 x 960 pixels imported resolution 96 ppi Gimp calculates that as 15" x 10"
2) I can scale that down to 12" x 8" The pixel size becomes 1152 x 768 and the 96 ppi I can leave alone if I want 12" x 8" print size.
3) If I want better print quality then I might increase the ppi to 300 The image size is still 1152 x 768 pix but now it will print with a size 3.84" x 2.56"
That is why you need to start off with a correct size in pixels Calculate Width (in inches) x 300 Height (in inches x 300)
Do not start off with some size in inches or mm and a default ppi of 72 or 96 and find that you have to scale the image.
Quote:Is there a difference in terms of quality or other thing, between doing from print size or scale?
When you know the image size in pixels is correct but the ppi is maybe a default value retained from importing, then change the Print Size ppi value There is no loss in quality, it is an internal setting used by the printer.
Scaling up or down involves interpolation, some pixels are thrown away (scaling down) or pixels are guessed (scaling up) and this results in some loss in quality Might be a lot / might be small.
How this fits in with the scale dialogue. Remember again Gimp works in pixels. Keep your eye on the size in pixels
1) The original image, 1440 x 960 pixels imported resolution 96 ppi Gimp calculates that as 15" x 10"
2) I can scale that down to 12" x 8" The pixel size becomes 1152 x 768 and the 96 ppi I can leave alone if I want 12" x 8" print size.
3) If I want better print quality then I might increase the ppi to 300 The image size is still 1152 x 768 pix but now it will print with a size 3.84" x 2.56"
That is why you need to start off with a correct size in pixels Calculate Width (in inches) x 300 Height (in inches x 300)
Do not start off with some size in inches or mm and a default ppi of 72 or 96 and find that you have to scale the image.