SketchIME

SketchIME is a SketchDataset loader for the SketchIME Dataset, which provides over 56K drawings across 374 categories. The dataset provides semantic annotations across 139 parts.

Source: datasets/sketchime.py

Data Format

Each sketch data is stored in a .json file. After loading the json file, we obtain a dict with the following keys:

  • key_id: file name of the json.

  • recog_label: category label, ranging from 0 to 373.

  • seg_label: a list of semantic part labels ranging from 0 to 139, each belongs to a path. Note that 139 is an invalid flag for padding.

  • stroke_num: a list of stroke numbers, each belongs to a path. Note that 0 is an invalid flag for padding.

  • sketch_stroke_num: the number of valid paths.

  • points_offsets: a list of point offsets on each path. Each path is a list of [dx, dy, p1, p2].

    • [dx, dy]: delta x/y coordinate, relative displacement from the previous point. The first one is [0.0, 0.0], which should be discarded.

    • [p1, p2]: can be [1.0, 0.0] (drawing / pen down), [0.0, 1.0] (lifting / pen up), and [0.0, 0.0] (for padding).

The loader converts the relative coordinates into absolute coordinates and then normalize them to a pre-defined image size.

Directory Layout

After download and extraction, the dataset is expected under:

<root>/
  .metadata.parquet
  SketchIME/
    cate_dir/
      001/
        C00101P08S001.json
        C00101P08S002.json
        ...
      002/
      ...
      374/

  • All sketch files are stored as .json files in each category directory 001 to 374.

Code

from sketchkit.datasets import SketchIME

ds = SketchIME(cislab_source=True)

sketch = ds[0]
print(sketch.width, sketch.height)
print(sketch.path_num, sketch.curve_num)

# Filter by category
sketch_items = ds.items_metadata[
    (ds.items_metadata["category"] == "001")
]
sketches = [ds[row.id] for _, row in sketch_items[:5].iterrows()]

Arguments

  • cislab_source: Selects the download source. If True, the dataset is downloaded from the CISLAB CDN mirror; otherwise it is downloaded from official host.

    • CISLAB mirror: https://cislab.hkust-gz.edu.cn/projects/sketchkit/datasets/SketchIME/SketchIME.zip

    • Official host: https://drive.google.com/file/d/1TbaK46IQvI6MCs0JpCcB1Fcx8Nr3i8g8

Metadata Columns

  • id: Global unique identifier across all sketches.

  • sub_id: Identifier within the specific category.

  • category: Drawing category name (e.g., “001”, “002”, etc.).

  • filename: The name of the json file.

  • split: Split in the dataset (e.g., “train”, “valid”, or “test”).

  • label_names: A string of part label names, separated by ‘;’ (e.g., “part1;part2;part3”).