# Graphics tool for Mac to define polygons on image and export points?



## mixedup (Jan 15, 2021)

Any advice re a graphics tool for Mac (ideally less expensive than PhotoShop if one supports this) that can:

1. Open a background image and scale to standard background size I need.
2. Define Areas - Define multiple areas on the image (e.g. Rect, Circle, Polygon) by tracing around key items (e.g. light, button, chair etc).
3. Export Area Data - Can export the data that describes these tracings (e.g. x,y co-ordinates for Polygon, position & radius for circle) when required. Would provide a list of data for each traced object, then can import into my application and read this. [could be just polygons only]
4. Export images for the areas defined from (2) - so after exporting for one images there might be several smaller images that would be exported (e.g. clipped image of the chair)
5. Can come back later and load/still have the areas defined, and adjust them and re-export data and images.
6. Overall output from one background image with areas defined on the image:
* Exports a data file defines the different areas (polygons etc)
* Exports the “cut out” images for each of these


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## vectorian (Sep 8, 2020)

Hi mixedup

Dont know ifwether i understand you right.
But i think what you are searching for is
call clipping mask.

Do you know Affinity Designer ?
This could be a choice for you.
Cost ca 60.- Euro one time fee, no
subscription.

Inkscape (free) could also be a choice.
The new 1.0 Version has cool features.


Affinity Designer/Inkscape are vector graphics programs
where you can cut out parts of an Bitmap in the way you
descripe. But, to mention this, Affinity Designer has
"no" vector tracing tool. Inkscape has one.

In Both you can clip out Parts of a Bitmap with a vector polygon,
also with a self painted. Just like the way you descripe it.

Hier a Link to a Video





Btw to get e.g. export the Area Data would be the hardest Part,
if not impossible at all. I would use .SVG for export, because the
.SVG file format saves the File Data as Text Commands. It has
some similaries to Html.
But .svg may only saves pure vector data, so that may not
work with your cutted Bitmap Parts. As a workaround you
can put a pure vector polygon twin over your bitmap part
and export this as .SVG .


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