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Good Morning:

I scanned my driver license photo into gimp 2.8.  I attempted to enlarge the image, using image ->scale image.   The pixel size of the image is 4754 X 3757.  Am I running up against the image being to dense to enlarge?  I had to go to a copy store  to enlarge the image, but there must be a way for me to accomplish this with gimp.
(10-03-2019, 10:32 AM)fmilling Wrote: [ -> ]I attempted to enlarge the image, using image ->scale image.  
That is the correct way to enlarge an image

Quote:The pixel size of the image is 4754 X 3757
Is that size of the image as scanned? Or the size after enlarging?
At 300 dpi (for a good quality print) 4754 X 3757 will give a print size of 402 x3 18mm

What is the size of the image as scanned? What size are you wanting to enlarge to?
Can you give more information.

An image 4754 x 3757 is a large image. Is the license photo just part of the image? Can you give details as the screenshot using Image -> Print Size  The size in inches / resolution.

[attachment=3218]

For a typical 2" x 2" ID photo all you need for photo quality is an image 600 x 600 pix. Printed at 300 ppi gives the correct size and quality.
I apologize if I wasn't clear, I am trying to enlarge the whole license. Secondly when I print it out it come out not like I expected but very small. Am I allowed to attach screenshot to this message? My scale seem very large goes from 0 to 4500 and image-print image my width is 11.885 and my height 9.39 inches. I would think i'd get a full page of the image. My dpi when I scan is set to 300 dpi is that to much?

Update I got it fellas. When I scanned the image in it was scanning to fit a 8x10 page. When I rescanned and adjusted the setting to fit the size of the license, then I was able to enlarge it. I appreciate the help Blighty and Rich2005. One last question. Any good book you would recommended for learning more about gimp?
Assumption: Size of license is 85 x 55 mm
Scanning at 300 dpi, this will give an image size of 1004 x 650 pixels

To print this image at 11.885 x 9.39 inches
1004/11.885 = 84 dpi
650/9.39 = 69 dpi
Very low resolution = blurry image

Scaling to higher image size before printing may or may not improve the printed image.
11.885 inches x 300dpi = 3565 pixels. Scale to this size.

Scanning at a higher resolution may or may not improve the final printed image
(If the actual license was printed at 300dpi scanning at a higher resolution won't help)
85 x 55 mm and scanning at 600 dpi
gives an image size of 2008 x 1300 pixels.
Less scaling is required.
With blurry images as Blighty says scanning at a higher resolution might help just try one step up then another see if that makes any difference,

another thing to try again there are no guarantees
goto
Filters > G'Mic-Qt > Details >

(here my pick of the filters again everyone's different opinion and results but it's a good start)

1 - Sharpen [Deblur]
2 - Sharpen [ Octave-Sharpening]
3 - Sharpen [Richardson-Lucy]

each image improves differently with each filter, make copies so you can compare one against the other if you want to,

A good book for Gimp is not something I would chase up because Gimp presently is evolving so quickly that any book published would probably be out dated by the time you get the book -
- best way I found was refer to the installed user's manual Ah your on windows just only get the manual from Gimp themselves no one else, I have my Gimp manual open whenever I use gimp, have it installed locally and use it when offline,

Useful site obvious but often forgotten Gimp >

https://www.gimp.org/

my favorite

https://www.gimp.org/tutorials/
(10-03-2019, 03:26 PM)fmilling Wrote: [ -> ]One last question.  Any good book you would recommended for learning more about gimp?

There is nothing recent, of the few that were published, they are based on Gimp 2.8 

A simple search will get some links: https://www.bettertechtips.com/photography/gimp-book/  complete with eye-watering prices. 

Not recommended.

For a copy of the Gimp 2.10 help in PDF form there is one here http://gimp.linux.it/www/meta/   43 MB 1000 pages

The best way to learn Gimp is still by use and learn as you go along.