Batch convert into webp

[meetdilip]

A friend of mine, who is into web development, optimises the images by making them small, say 13 -20 KB. He uses Photopea to get his favourite image size at 2000 x 1309 px and exports it into webp format.

I am amazed that he manages to convert even full HD images in the 15 - 25 KB range. Wondering if we can do that same in GIMP. And apply it a number of images. Thanks.

PS: I do have BIMP installed. But not sure how to use properly for this use case.

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The best I could do was 1.4 MB from Unsplash to 422 KB using resize and then convert to webp.

[PixLab]

Quote:Wondering if we can do that same in GIMP

Indeed you can, when you export just add the extension .webp and the webp parameters window will appear after clicking the "Export" button.
If you got more than one layer, you can even export as webp animation

   

[rich2005]

(06-16-2022, 03:23 PM)meetdilip Wrote: A friend of mine, who is into web development, optimises the images by making them small, say 13 -20 KB. He uses Photopea to get his favourite image size at 2000 x 1309 px and exports it into webp format.

I am amazed that he manages to convert even full HD images in the 15 - 25 KB range. Wondering if we can do that same in GIMP. And apply it a number of images. Thanks.

PS: I do have BIMP installed. But not sure how to use properly for this use case.

---

The best I could do was 1.4 MB from Unsplash to 422 KB using resize and then convert to webp.

It can depend on the format your friend uses. Multi-layer psd will be a problem. For single layer formats
Set up BIMP like this:

   

The resize with aspect ratio will scale to 2000 pix for the longest size,
The change format and compression for webp - set as required.

Have to say 2000x1309 pix is a strange size. What is the original image size ? To get anything down to 13 - 25 KB the images must be mostly single colour simple graphic. Can you give details.

Edit: Maybe as a guide: This is your stationary template (yes, I did get it eventually using Tor) original size 5352x3688 scaled down to 2000 pix wide. Exported as a webp with 30 quality (not a lot of file size difference between 60 - 50 - 40 -30 quality ) . File size 36.5 KB Getting smaller than that, probably have to scale to less than 2000 pix https://ibb.co/WnDskn7

[meetdilip]

Thanks PixLab , admin

I will update you in detail by evening. Will talk to the person about this and try to understand how he is doing.

Quote:What is the original image size ?

In most cases, images are downloaded from Unsplash as PNG.

[Ofnuts]

Webp can be slightly better than JPEG on photography (smaller file size for the same perceived quality) but there are no miracles: you can possibly shave off 20% of the file size. You could get more out of tuning your JPEG parameters (in particular the chroma subsampling).

[meetdilip]

I agree. At least I now have the best method to batch convert images.

Thanks for all the help.

[rich2005]

I think for graphic images other than photographs, a webp might be 50% of a jpeg. (same image 80%, half chroma jpeg vs. 60 compression webp )

When saving either format remember to untick all those 'Save profile / thumbnail / 'xxx' data options which just add to the file size.

[meetdilip]

Quote:When saving either format remember to untick all those 'Save profile / thumbnail / 'xxx' data options which just add to the file size.

I always thought they were necessary.

[rich2005]

(06-17-2022, 11:04 PM)meetdilip Wrote:

Quote:When saving either format remember to untick all those 'Save profile / thumbnail / 'xxx' data options which just add to the file size.

I always thought they were necessary.

More applicable to photographs, than graphic design. The file can contain information (metadata) that the creator does not want to share. It can be sizeable as well, some icc profiles and comments.  Your stationary psd for example contains 

    xmp:CreateDate: 2021-06-15T11:54:24+02:00
    xmp:CreatorTool: Adobe Photoshop CC (Windows)
    xmp:MetadataDate: 2021-08-21T20:46:29+02:00
    ........
  Profiles:
    Profile-8bim: 22880 bytes
    Profile-exif: 430 bytes
    Profile-icc: 560 bytes
    Profile-iptc: 58 bytes
      City[1,90]: 0x00000000: 254700                                       
      Copyright String[2,116]: Freepik Company S.L. - http://www.freepik.com
    Profile-psd:additional-info: 2096 bytes

Ah-ha...got it from freepick, not your original work and also those extra profile bytes if your intention is the smallest possible filesize while retaining quality.

There are small utilities that can be used, in linux look for pngcrush and jpegoptim (or trimage which combines those)
or
A typical online: https://www.toolsley.com/jpegstrip.html

[meetdilip]

Thanks. I will experiment on a few files