Cropping - Custom Crop Guides

[SpiDeeWebb]

Hello All,

Bottom Line Up Front: I want to create a new cropping guide for passports.

I'm having a little trouble with terminology. 

I can't figure out what the heck developers refer to these as.

I'm seeing under the presets they're just referred to simply as 'guide center-line' 'guide rule-of-thirds.'
I thought it'd be a simple matter of loading it up in GCC searching the right term, and playing around with it.

I just can't for the life of me find them to begin with.

[rich2005]

You need to give more information about what you need to achieve.

Is it cropping out a whole page of a passport?
Is it cropping out perhaps a photograph? - that is popular
Do you want to size and crop an existing portrait suitable for a passport image?
...or anything else...

When it comes to the crop tool, the preset guides are really meant for photographers wanting to compose their work with emphasis on certain sections of the image. hence the rule-of-thirds, golden section etc. Probably the only one that might be applicable is the center-lines.

There are other ways than the crop tool to trim an image to size. Back to what is the purpose.

If you can post an example, even better.

(Out of interest, do you really use Windows and Linux and OSX as operation systems? )

[Kevin]

I'd start by searching for the exact text of one of the guide options:

Code:

Searching for: Golden sections
app\display\display-enums.c(64): { GIMP_GUIDES_GOLDEN, NC_("guides-type", "Golden sections"), NULL },
app\display\display-enums.h(44): GIMP_GUIDES_GOLDEN,        /*< desc="Golden sections" >*/
Found 2 occurrence(s) in 2 file(s)

So then I'd search for GIMP_GUIDES_GOLDEN, which should find where the code is that implements drawing them:

Code:

Searching for: GIMP_GUIDES_GOLDEN
app\display\display-enums.c(51): { GIMP_GUIDES_GOLDEN, "GIMP_GUIDES_GOLDEN", "golden" },
app\display\display-enums.c(64): { GIMP_GUIDES_GOLDEN, NC_("guides-type", "Golden sections"), NULL },
app\display\display-enums.h(44): GIMP_GUIDES_GOLDEN,        /*< desc="Golden sections" >*/
app\display\gimpcanvasrectangleguides.c(311): case GIMP_GUIDES_GOLDEN:
app\display\gimpcanvastransformguides.c(419): case GIMP_GUIDES_GOLDEN:
Found 5 occurrence(s) in 4 file(s)

Then I'll leave it to you to get lost in the mass of code

[Blighty]

(10-04-2017, 07:33 AM)SpiDeeWebb Wrote: Bottom Line Up Front: I want to create a new cropping guide for passports.

I am not understanding what you are wanting to do. Are wanting to crop images of passports? Or are you wanting to crop photos that will be used in passports?

What constraints do you have in terms of size, resolution, aspect ratio, etc? There must be some spec.
How much variation is there in the originals in terms of size, etc?

[Ofnuts]

(10-04-2017, 08:08 AM)rich2005 Wrote: You need to give more information about what you need to achieve.

Is it cropping out a whole page of a passport?
Is it cropping out perhaps a photograph? - that is popular
Do you want to size and crop an existing portrait suitable for a passport image?
...or anything else...

When it comes to the crop tool, the preset guides are really meant for photographers wanting to compose their work with emphasis on certain sections of the image. hence the rule-of-thirds, golden section etc. Probably the only one that might be applicable is the center-lines.

There are other ways than the crop tool to trim an image to size. Back to what is the purpose.

If you can post an example, even better.

(Out of interest, do you really use Windows and Linux and OSX as operation systems? )

I think the OP wants something that s/he can align with the nose/mouth/eyes of the subject to generate a crop with the rather stringent rules of
passport photography.

If I were to do such a thing, I would create a path that I would import in the picture (one keystroke with the proper script),  then align over the layer (possibly scaling the layer or the path), and then use specific points in the path to crop the layer (another single keystroke with the proper script).

If a specific final size in pixels is requested then one can use fixed guides, and therefore use ofn-preset-guides to generate & load a custom set of guides.

[rich2005]

Yes, once the requirements are defined, some automation is possible. A straight passeport photo was one that I thought might be a possibility, but my crystal ball is broken

Very unlikely to be just a straight crop. As pointed out, different places have different requirements, size of printed image for one, which brings in the subject of ppi. Then certain proportions on that image say, top of head to bottom of chin, colour of background, no smiling, no spectacles, at least one ear showing. All sorts.

Guides needed, maybe scaling and moving needed before cropping is considered or even needed.

An example, https://i.imgur.com/JvNNKh7.jpg and definitely no smiling.