I'm creating some textures for 3d models using gimp. I've been exporting as jpg
with quality set at 100, but the file sizes are humongous. What do you think is
the best setting to bring down the file size with no noticeable loss of quality?

Well, I would simply experiment and decide what is "best for you"

Open original, export as new-name1.jpg at say 70% Then reopen original, and export as new-name2.jpg at say 60% and so on

Most of my saves are at 50%

Why jpgs? What sizes do you get with pngs?

Owen

On Thu, May 22, 2014 at 2:30 AM, Owen wrote:

I'm creating some textures for 3d models using gimp. I've been exporting as jpg
with quality set at 100, but the file sizes are humongous. What do you think is
the best setting to bring down the file size with no noticeable loss of quality?

Well, I would simply experiment and decide what is "best for you"

Open original, export as new-name1.jpg at say 70% Then reopen original, and export as new-name2.jpg at say 60% and so on

Most of my saves are at 50%

Why jpgs? What sizes do you get with pngs?

It is indeed hard to give a perfect number out of the box. The overall visual quality is very much dependent on what the image actually depicts and on what kind of compromise you can tolerate. A dirt texture can probably pull off a much lower quality than a smooth gradient.

On 05/22/14 07:08, Sren Pilgrd wrote:

On Thu, May 22, 2014 at 2:30 AM, Owen wrote:

I'm creating some textures for 3d models using gimp. I've been exporting as jpg
with quality set at 100, but the file sizes are humongous. What do you think is
the best setting to bring down the file size with no noticeable loss of quality?

Well, I would simply experiment and decide what is "best for you"

Open original, export as new-name1.jpg at say 70% Then reopen original, and export as new-name2.jpg at say 60% and so on

Most of my saves are at 50%

Why jpgs? What sizes do you get with pngs?

It is indeed hard to give a perfect number out of the box. The overall visual quality is very much dependent on what the image actually depicts and on what kind of compromise you can tolerate. A dirt texture can probably pull off a much lower quality than a smooth gradient.

First, make sure the image is down-sized to something like 1280 x 1024 or less. Then turn on the preview in the jpeg export dialog. That will tell you both how large the file will be, and you can view the preview to see what it will look like. Decrease or increase the percentage until you're happy with the compromise.

Gary

On Thu, 22 May 2014 02:20:31 +0200, weswood wrote:

What do you think is
the best setting to bring down the file size with no noticeable loss of quality?

95 is the maximum you should use - there's no perceptual difference between 95 and 100, but the size increase is huge.

Anyway, with most images you can go even lower - when exporting a JPEG, tick the Preview checkbox, and play with the settings. You should always enable both Progressive and Optimize, as those losslessly reduce the file size, and switch the DCT mode to Floating point (slightly improves quality, and usually reduces the file size). Try also different subsampling options - depending on image content, you can get quite a size reduction while having very little visual difference.

< Jernej Simončič ><><><><>< http://eternallybored.org/ >

On Thu, 2014-05-22 at 17:01 +0200, weswood wrote:

First, make sure the image is down-sized to something like 1280 x 1024 or >less. Then turn on the preview in the jpeg export dialog.

[...]

After saving, you can run jpegoptim - in some cases this will get significant file size savings with no loss in image quality.

Check the image still opens afterwards, though - I've had occasional problems.

Liam Quin - XML Activity Lead, W3C, http://www.w3.org/People/Quin/
Pictures from old books: http://fromoldbooks.org/
Ankh: irc.sorcery.net irc.gnome.org freenode/#xml