Alternatively, LDB also understands the scheme where multiple data objects are described in a single JSON file residing at root folder
There is no option to accomplish this (afaik).
LDB ships with a pre-processor for COCO, ImageNet, Google OpenImage, and general folder-class schemes. hese can be selected during indexing with --format argument providing the format:
There are no such options.
Additional formats can be included by writing the custom pre-processors.
In https://github.com/iterative/ldb-resources/blob/main/documentation/Getting-started-with-LDB.md#indexing-data-in-various-formats there are a few misleading parts:
There is no option to accomplish this (afaik).
There are no such options.
It is not possible.