New filter 'Deformations / Seamcarve'

Ronounours · **Joined:** Jan 03, 2011 **Posts:** 1656

Hi there,

We have added a new cool filter in the G'MIC plug-in for GIMP today, namely the Seamcarve filter that you will find in the Deformations/[b] folder.
This filter is basically similar to what the Liquid Rescale plug-in does: it implements the well known [b]Seam-carving algorithm for image upscaling/downscaling.
More precisely, It iteratively removes or adds seams of pixels so that the less important image structures are removed/duplicated first. This way, one can upscale/downscale images along one dimension without modifying the aspect ratio of the objects located in the image.

Here is how the filter interface looks:

Attachment:

gmic_seamcarve.png [ 256.05 KiB | Viewed 5049 times ]

And some examples of use. First for image downscaling. Note how the image width is reduced without distorting the gulls.

Attachment:

gulls_all.jpg [ 510.53 KiB | Viewed 5049 times ]

Another example, for image upscaling this time.

Attachment:

bridge_all.jpg [ 376.99 KiB | Viewed 5049 times ]

Just update your filters, and you should be able to use it. Enjoy !

Ronounours · **Joined:** Jan 03, 2011 **Posts:** 1656

Another example I've made for image downscaling :

Attachment:

tower_all.jpg [ 247.23 KiB | Viewed 5049 times ]

molly · **Joined:** Apr 07, 2010 **Posts:** 14182

Very cool David... looks good

dinasset · **Posted:** Mon Jun 02, 2014 8:57 am **(#4)**

David,
what's wrong with my first trial?
(my intention was to keep the central part untouched while enlarging the area around)

Attachment:

before.xcf [602.17 KiB]
Downloaded 185 times

Attachment:

after.xcf [749.17 KiB]
Downloaded 177 times

input layer=all

Ronounours · **Joined:** Jan 03, 2011 **Posts:** 1656

dinasset, you probably forgot to set the "Use top layer as a priority mask" checkbox ?
I get this :

Attachment:

gmic_seamcarve2.png [ 286.9 KiB | Viewed 5022 times ]

And when I click 'Apply', I get this :

Attachment:

gmic_seamcarve3.jpg [ 86.82 KiB | Viewed 5022 times ]

David.

The Warrior · **Joined:** Jun 02, 2013 **Posts:** 2090

That's incredible, love it.

dinasset · **Posted:** Mon Jun 02, 2014 9:15 am **(#7)**

you are perfectly right, David!!!
sorry...
I repeated and got your same result.
Extremely useful filter, there is a lot of situations in which there is a need to modify the ratio of an image leaving important subjects as they are.
Thanks a lot, David!!! Excellent!

pirate541 · **Joined:** May 27, 2011 **Posts:** 707

I keep getting message saying priority top layer is missing

dinasset · **Posted:** Mon Jun 02, 2014 9:31 am **(#9)**

did you set input layer=all?

pirate541 · **Joined:** May 27, 2011 **Posts:** 707

yes i did

dinasset · **Posted:** Mon Jun 02, 2014 9:43 am **(#11)**

it happens if you just copy my xcf file "input" (I don't know why)
click on the image layer, edit-copy, paste as new image, create your own mask on top, start gmic, input layers=all, use mask on ... and it works

post-scriptum: I understood why the simple copy of my xcf input file doesn't work: the mask layer colour is not copied correctly as TRUE GREEN (00FF00)!!!

skullquake · **Joined:** Jun 01, 2014 **Posts:** 11

Very freaky...

dinasset · **Posted:** Mon Jun 02, 2014 2:37 pm **(#13)**

skullquake wrote:

Very freaky...

probably something went wrong when I saved the .xcf on my desktop
anyhow, when using masks, it's always safe to check the real colour... pure red or pure green!

pirate541 · **Joined:** May 27, 2011 **Posts:** 707

dina
I am sorry,but I don't get it

dinasset · **Posted:** Tue Jun 03, 2014 5:18 am **(#15)**

pirate541 wrote:

dina
I am sorry,but I don't get it

pirate
-open any image you want (I took 1274-fun123)

Attachment:

1274_fun123.jpg [ 636.91 KiB | Viewed 2820 times ]

-add a layer on top transparent
-choose as foreground color 00ff00 (pure green)
-paint with the pencil tool using foreground color over the whole cube (see xcf)

Attachment:

1274_fun123.7z [643.82 KiB]
Downloaded 107 times

-call gmic filter
-select input layers = all
-select use top layer as mask
-select output = new (just to keep your input for next experiments)
-enter width = 185%
-run the filter
I show you my result

Attachment:

after-filter.png [ 678.86 KiB | Viewed 2820 times ]

try again...

dinasset · **Posted:** Tue Jun 03, 2014 7:52 am **(#16)**

David,
I used many times successfully the filter with the "green" mask (keep object)
I was not as successful with the "red" mask (remove object)
What's wrong with my test?
here input and output (parameters: all layers, top layer as mask, default 85% width)

Attachment:

Image5-resized.7z [1.24 MiB]
Downloaded 107 times

Attachment:

resulting-as.7z [1.05 MiB]
Downloaded 111 times

dinasset · **Posted:** Tue Jun 03, 2014 8:11 am **(#17)**

for those who like to see flatten input/output (without the need to unzip/load xcf)

Attachment:

Image5-resized-input.png [ 1.28 MiB | Viewed 2802 times ]

Attachment:

resulting-as-.png [ 973.63 KiB | Viewed 2802 times ]

dinasset · **Posted:** Tue Jun 03, 2014 11:03 am **(#18)**

made some additional test and -from my side- I confirm:
- with "green" mask everything goes OK
- with "red" mask it is simply ignored (checked: red is red: ff0000)

garagecoder · **Posted:** Tue Jun 03, 2014 2:07 pm **(#19)**

Just a quick note to say I'm having a think about how the mask for keep/remove can be improved, it might take me a day or two to come up with something suitable so please be patient :yup

Also be aware the latest G'MIC 1.5.9.1 has quite a nice speed boost for this so if you're finding it slow updating might help.

Ronounours · **Joined:** Jan 03, 2011 **Posts:** 1656

dinasset, I've just updated the filter, it should work better now with green/red regions on top layer.