# RFC: New "format" to store custom annotation for a custom slicer application

**URL:** <https://discourse.slicer.org/t/rfc-new-format-to-store-custom-annotation-for-a-custom-slicer-application/17005>\
**Category:** Development\
**Created:** [April 8, 2021, 5:58pm UTC](https://discourse.slicer.org/t/rfc-new-format-to-store-custom-annotation-for-a-custom-slicer-application/17005 "2021-04-08T17:58:46Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![jcfr](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jcfr/32/17825_2.png) [@jcfr](https://discourse.slicer.org/u/jcfr)\
**Post date:** [April 8, 2021, 5:58pm UTC](https://discourse.slicer.org/t/rfc-new-format-to-store-custom-annotation-for-a-custom-slicer-application/17005/1 "2021-04-08T17:58:46Z")

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In the context of the [Cell Locator](https://github.com/BICCN/cell-locator#readme) project, a Slicer-based custom application to manually aligning specimens to annotated 3D spaces, we developed a json-based format to store annotation.

### Current

Until now the format has been used internally to the application

The current cell-locator format is similar to the markup json format expect it removes/includes few additional properties.

See [https://github.com/BICCN/cell-locator/blob/master/Documentation/AnnotationFileFormat.md#2020-09-18](https://github.com/BICCN/cell-locator/blob/master/Documentation/AnnotationFileFormat.md#2020-09-18)

### Proposed plan

To support the reading/loading of annotation by other application, we are now considering the following:

1. “standardizing” it by including version information and schema similarly to what we already do for the json file associated with markups (see [markups-schema-v1.0.1.json](https://github.com/Slicer/Slicer/blob/master/Modules/Loadable/Markups/Resources/Schema/markups-schema-v1.0.1.json))

2. creating standalone python tool for converting between version and streamline batch migration

3. ensure the application automatically convert older format to newer ones.

### Questions

- Should we consider building on existing format or standard ?

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**Author:** ![pieper](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pieper/32/8_2.png) [@pieper](https://discourse.slicer.org/u/pieper)\
**Post date:** [April 8, 2021, 6:19pm UTC](https://discourse.slicer.org/t/rfc-new-format-to-store-custom-annotation-for-a-custom-slicer-application/17005/2 "2021-04-08T18:19:49Z")

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This is a very timely question. There are similar efforts around dicom SR encodings of annotations and quantitative results which may share some interests but maybe not others. Doing something application-specific is easiest to maintain of course, but I would love to see it standardized.