Sign up now! · Forgot password?
RSS/Atom feed identi.ca Twitter

resizing image creates blurry image

This discussion is connected to the gimp-user-list.gnome.org mailing list which is provided by the GIMP developers and not related to gimpusers.com.

6 of 6 messages available
Toggle history

Please log in to manage your subscriptions.

resizing image creates blurry image firefly24 09 Nov 18:21
  resizing image creates blurry image Metella 11 Nov 13:39
  resizing image creates blurry image Owen 12 Nov 09:25
   resizing image creates blurry image Metella 12 Nov 12:17
  resizing image creates blurry image Liam R E Quin 12 Nov 16:27
   resizing image creates blurry image firefly24 12 Nov 16:39
2018-11-09 18:21:10 UTC (7 days ago)
postings
2
contact
Send private message

resizing image creates blurry image

I'm trying to resize an image from 398x398 to 28x28. I've followed several guides and each time gives me the same effect.

Things I've tried:

1. Resize to 28x28 using NoHalo 2. Apply Gaussian blur then resize using NoHalo, finally using Unsharp Mask to sharpen 3. Resize to 28x28 using LoHalo
4. Apply Gaussian blur then resize using LoHalo, finally using Unsharp Mask to sharpen

each of them came out with the same effect of the image being blurry. I'm not sure what I'm doing wrong and none of the guides I've seen seem to help.

2018-11-11 13:39:59 UTC (5 days ago)
postings
3
contact
Send private message

resizing image creates blurry image

I Hope someone helps with this - I also have an image that looks like too few pixels and is blurry - ish - ---

As someone learning - and decent at the basics - I find it difficult to get specific help - and dealing with Book Covers for Ingramspark and KDP - they are Exacting in what they will accept - and I find it hard to do the little things at the end of all the hard artistic work to get the covers accepted ... I'll be watching this thread ....

Owen
2018-11-12 09:25:32 UTC (5 days ago)

resizing image creates blurry image

Are you talking pixels as the unit, ie, 398x398 pixels and trying to reduce that to 28x28 pixels.

If so, I think you are going to be out of luck as the reduction is too great.

Using reductio ad absurdum, what would you expect if you tried to reduce the image to 1x1 pixel?

You cannot expect to have anything like the same information (image likeness) when reduced to such a small amount, approx .6% of the original).

Owen

I'm trying to resize an image from 398x398 to 28x28. I've followed several guides and each time gives me the same effect.

Things I've tried:

1. Resize to 28x28 using NoHalo 2. Apply Gaussian blur then resize using NoHalo, finally using Unsharp Mask to sharpen
3. Resize to 28x28 using LoHalo
4. Apply Gaussian blur then resize using LoHalo, finally using Unsharp Mask to sharpen

each of them came out with the same effect of the image being blurry. I'm not sure what I'm doing wrong and none of the guides I've seen seem to help.

2018-11-12 12:17:42 UTC (5 days ago)
postings
3
contact
Send private message

resizing image creates blurry image

WOW - you are assuming the worst of me - I guess newbies overall do that do people ...

but not - I want increased definition MORE pixels - I can get the error notice from ingramspark if seeing that will help you ... ???

Anyway - thanks for answering - we need a more vibrant help community here for GIMP since the other options are literally robbing all new start up users.

Liam R E Quin
2018-11-12 16:27:31 UTC (4 days ago)

resizing image creates blurry image

On Fri, 2018-11-09 at 19:21 +0100, firefly24 wrote:

I'm trying to resize an image from 398x398 to 28x28.

Since 398 isn't an exact multiple of 28, it may help to crop it first to 392 pixels by 392. Then scale down to 1/7th the size (56 x 56) and use curves to make sure you still have contrast, then scale down 2x to 14x14 and sharpen.

Make sure the image is in 16bpp or 32bpp precision (assuming Gimp 2.10) and RGB, not indexed.

Without seeing the original image it's hard to give better advice. The images on the front of fromoldbooks.org are mostly scaled down with Gimp in lohalo mode, often to between 1% and 3% of the original height, but at 200x300 pixels i have a chance of sme detail.

slave ankh

Liam Quin - web slave for https://www.fromoldbooks.org/
with fabulous vintage art and fascinating texts to read.
Click here to have the slave let out of its cage to do chores.
2018-11-12 16:39:17 UTC (4 days ago)
postings
2
contact
Send private message

resizing image creates blurry image

Since 398 isn't an exact multiple of 28, it may help to crop it first to 392 pixels by 392. Then scale down to 1/7th the size (56 x 56) and use curves to make sure you still have contrast, then scale down 2x to 14x14 and sharpen.

Make sure the image is in 16bpp or 32bpp precision (assuming Gimp 2.10)
and RGB, not indexed.

Without seeing the original image it's hard to give better advice. The images on the front of fromoldbooks.org are mostly scaled down with Gimp in lohalo mode, often to between 1% and 3% of the original height,
but at 200x300 pixels i have a chance of sme detail.

slave ankh

Thank you for the advice. I'll try that. Attached is the original image. I've also converted to svg as well to try and better handle the scaling.