Adding support for writing transformed images/videos to new location/field

[brimoor]

Small enhancement that adds support for optionally writing transformed images/videos to a new output location, and storing the resulting filepaths in a new field.

This new syntax is useful, for example, for quickly generating thumbnail images for a dataset.

Python examples

import shutil

import fiftyone as fo
import fiftyone.zoo as foz
import fiftyone.utils.image as foui
import fiftyone.utils.video as fouv

# Image example
dataset = foz.load_zoo_dataset("quickstart")

foui.transform_images(
    dataset,
    size=(-1, 64),
    output_field="thumbnail_path",
    output_dir="/tmp/thumbnails",
    rel_dir=fo.config.dataset_zoo_dir,
)

print(dataset.select_fields("thumbnail_path").first())

# Video example
dataset = foz.load_zoo_dataset("quickstart-video")

fouv.transform_videos(
    dataset,
    size=(-1, 128),
    output_field="thumbnail_path",
    output_dir="/tmp/thumbnails",
    rel_dir=fo.config.dataset_zoo_dir,
)

print(dataset.select_fields("thumbnail_path").first())

# Cleanup
shutil.rmtree("/tmp/thumbnails")

CLI examples

ZOO_DIR=$(fiftyone config dataset_zoo_dir)

# Image example
fiftyone zoo datasets load quickstart

fiftyone utils transform-images quickstart \
    --max-size='-1,64' \
    --output-field thumbnail_path \
    --output-dir /tmp/thumbnails \
    --rel-dir $ZOO_DIR

ls -lah $ZOO_DIR/quickstart/data | head

# Video example
fiftyone zoo datasets load quickstart-video

fiftyone utils transform-videos quickstart-video \
    --max-size='-1,128' \
    --output-field thumbnail_path \
    --output-dir /tmp/thumbnails \
    --rel-dir $ZOO_DIR

ls -lah $ZOO_DIR/quickstart-video/data | head

# Cleanup
fiftyone datasets delete quickstart
fiftyone datasets delete quickstart-video
rm -rf /tmp/thumbnails

[benjaminpkane]

LGTM