Enlarging Image

[fmilling]

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.

[Blighty]

(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?

[rich2005]

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.

   

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.

[fmilling]

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?

[Blighty]

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.

[Redraw]

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/

[rich2005]

(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.