This is a summary of a slack discussion, started by
Storing Annotated Drawings as Raster-Images-with-Alpha
For 2D media ( image-sequences/quicktimes ) reviews, what is the value we are providing to artists and reviewers by storing the reviewer's annotated drawings as a vector ?Can't we just render the annotated drawings created by a reviewer on respective frames into raster-images-with-alpha using a format such as PNG ?And then, when the artist or reviewer wants to see that annotation that was done on a particular version of daily media ( image-sequence/quicktime ) we can just overlay the appropriate annotated raster-image-with-alpha on top right ?
Q: Sam: Does the alpha contain the brushstrokes for the annotations rather than the original image alpha?
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Advantages of using Annotated-Raster-Images-with-Alpha :
- Since these annotated-raster-images-with-alpha will be rendered with the same resolution as the daily ( image-sequence/quicktime ) on top of which they were drawn on, the annotated-raster-images-with-alpha will always preserve the same quality as the daily ( image-sequence/quicktime ) no matter what device they are played on.
- Even when the resolution of the daily (image-sequence/quicktime ) needs to changed to create a down-rezed proxy, the same down-rezing can also be done to the annotated-raster-images-with-alpha.
- The same is true even when you need to crop the daily (image-sequence/quicktime ), you can do the same cropping to the corresponding annotated-raster-images-with-alpha .
- And since we are storing only the annotated-drawings ( and not redundantly storing the image below ) as raster-images-with-alpha the file size of these will also be small.
- And since we are literally creating a rendered annotated-raster-image-with-alpha, there is no limitation to the drawing tools ( brushes, strokes, symbols, stickers, emojis, etc. ) that a reviewer can use while doing their reviews.
- Reproducibility is a bit of a concern (missing fonts, different text or emoji rendering, etc.), whereas with raster images you see exactly what the annotator saw, even though you may not be able to re-create it in your tool / on your system.
Advantages in using Vector Annotations:
- At-least based on my limited understanding, for 2D reviews, the only advantage of storing annotations as vectors is, after importing back a vector-annotation we will be able to edit/modify the annotated vector strokes more easily. But 90% of the time, reviewers/artists won't be editing/modifying already drawn annotations right ? - Sam: The assumption is that we are not editing them.
- For reviewing in a 3D space storing the annotated strokes as vectors will be beneficial.
- Vectors are much smaller data for the average annotation. They therefore transfer more easily in sync sessions. For more complex annotations a raster image might become smaller.
- Vectors map better to the recorded input so it's easier to develop with, because you don't have to manage undo stacks with different data
- Easier to append metadata like user id to strokes with vectors for multi session recordings, also useful to timestamp strokes to align them to audio/speech to text.
- For the case where text is part of the annotation, the text can be searchable.
- Much easier to have a single file containing summary of a review, including all notes and annotations.