MUSTARD / README.md
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metadata
license: mit
task_categories:
  - image-to-text
language:
  - en
  - hi
  - te
  - ta
  - or
  - ur
  - ml
  - zh
  - pa
  - gu
  - bn
  - as
  - kn
tags:
  - table
  - table-structure-recognition
  - TSR
  - multilingual
  - OTSL
  - historical-documents
size_categories:
  - 1K<n<10K
configs:
  - config_name: default
    data_splits:
      - test

MUSTARD

A structured repackaging of badrivishalk/MUSTARD that surfaces the OTSL annotations and language metadata as proper dataset columns.

MUSTARD (Multilingual Scanned and Scene Table Structure Recognition Dataset) contains 1,429 table images across 13 languages, annotated with OTSL (Optimized Table Structure Language) sequences for table structure recognition. Introduced by the SPRINT paper (ICDAR 2024).

This is an evaluation-only benchmark (test split only, no train).

Why this version

The original upload uses imagefolder format, which means the OTSL annotations in merged.txt are not exposed as columns in the dataset viewer or via load_dataset. Loading it returns only {"image": ...} with no annotation access.

This version gives you:

{
  "image_id":    "indic/assamese/1",         # stable identifier
  "image":       <PIL Image>,
  "width":       2210,
  "height":      1394,
  "language":    "assamese",                 # 13 values
  "script_type": "indic",                    # "indic" or "scenetext"
  "has_lines":   True,                       # scenetext: whether grid lines visible
  "otsl":        "FFFLFFFNUUFFUUUN...",
  "n_rows":      10,
  "n_cols":      7,
}

Schema

Field Type Description
image_id string Stable path-derived identifier (e.g. indic/assamese/1, scenetext/chinese_lines/1)
image Image Table image (PNG)
width int32 Image width in pixels
height int32 Image height in pixels
language string One of 13 languages (see table below)
script_type string "indic" for printed/scanned Indic-script tables; "scenetext" for scene-text tables
has_lines bool For scenetext: whether the table has visible grid lines. Always True for indic.
otsl string OTSL annotation sequence (see format below)
n_rows int32 Number of table rows decoded from OTSL
n_cols int32 Number of table columns decoded from OTSL (max row width)

Language distribution

Language Script type Count
assamese indic 101
bengali indic 100
chinese indic + scenetext 207
english scenetext 109
gujarati indic 101
hindi indic 101
kannada indic 101
malayalam indic 102
oriya indic 101
punjabi indic 102
tamil indic 100
telugu indic 102
urdu indic 102
Total 1,429

Scenetext subset: 111 with visible grid lines (has_lines=True), 103 without (has_lines=False).

OTSL format

OTSL (Optimized Table Structure Language) encodes table structure as a flat token sequence. Rows are delimited by N; within each row, each character is one cell:

Token Meaning
F Regular cell (no span)
L Cell spanning left (continuation of the cell immediately to its left)
U Cell spanning up (continuation of the cell directly above)
E Cell spanning both left and up (interior merge corner)
X Empty/non-data cell

Example: FFLNFFN = a 2-row, 3-column table where row 1 has a merged cell in columns 2-3 (F F L) and row 2 is all regular cells (F F).

Decode OTSL to an HTML table

def otsl_to_html(otsl: str) -> str:
    rows = [r for r in otsl.split("N") if r]
    n_cols = max(len(r) for r in rows)

    # First pass: compute colspan/rowspan
    grid = [[None] * n_cols for _ in range(len(rows))]
    spans = {}

    for r, row in enumerate(rows):
        for c, tok in enumerate(row):
            if tok == "F":
                spans[(r, c)] = [1, 1]
                grid[r][c] = (r, c)
            elif tok == "L":
                origin = grid[r][c - 1]
                spans[origin][1] += 1
                grid[r][c] = origin
            elif tok == "U":
                origin = grid[r - 1][c]
                spans[origin][0] += 1
                grid[r][c] = origin
            elif tok == "E":
                origin = grid[r - 1][c - 1]
                grid[r][c] = origin

    # Second pass: emit HTML
    html = ["<table>"]
    for r, row in enumerate(rows):
        html.append("  <tr>")
        for c in range(len(row)):
            if grid[r][c] == (r, c):
                rs, cs = spans[(r, c)]
                attrs = ""
                if rs > 1:
                    attrs += f' rowspan="{rs}"'
                if cs > 1:
                    attrs += f' colspan="{cs}"'
                html.append(f"    <td{attrs}></td>")
        html.append("  </tr>")
    html.append("</table>")
    return "\n".join(html)

Usage

from datasets import load_dataset

ds = load_dataset("rootsautomation/MUSTARD", split="test")

# Filter to a single language
hindi = ds.filter(lambda x: x["language"] == "hindi")

# Filter to scenetext with lines
scene_lines = ds.filter(lambda x: x["script_type"] == "scenetext" and x["has_lines"])

# Access a sample
row = ds[0]
print(row["language"], row["n_rows"], "x", row["n_cols"])
row["image"].show()

License

MIT. Source data curated by the IIT Bombay LEAP OCR Team. See badrivishalk/MUSTARD for the original release.

Citation

@inproceedings{sprint2024,
  title     = {SPRINT: Script-agnostic Structure Recognition in Tables},
  booktitle = {Document Analysis and Recognition -- ICDAR 2024},
  year      = {2024},
  note      = {arXiv:2503.11932}
}