| --- |
| license: cc-by-4.0 |
| task_categories: |
| - image-to-text |
| tags: |
| - charts |
| - chart-understanding |
| - data-extraction |
| - benchmark |
| - synthetic |
| size_categories: |
| - n<1K |
| configs: |
| - config_name: default |
| data_files: metadata.jsonl |
| --- |
| |
| # ChartParse-Bench |
|
|
| 58 synthetic charts whose exact values were written **before the pixels existed**. |
|
|
| Every gate in chart extraction measures self-consistency: redraw the extraction, check it |
| lands on the same ink, call it verified. That passes a series traced confidently off the |
| wrong axis. Because each chart here ships the array it was drawn from, the question stops |
| being *is this answer plausible* and becomes *is this answer right*. |
|
|
| ## Contents |
|
|
| | family | charts | series | what it isolates | |
| |---|--:|--:|---| |
| | A — line | 18 | 62 | identity through crossings, resampling honesty, axis binding | |
| | B — scatter | 11 | 22 | recall under overplotting, size/shape channels, outliers | |
| | C — area | 9 | 29 | stacking, computed baselines, composited fills | |
| | D — compound | 12 | 43 | non-Cartesian frames, linked panels, mixed geometries | |
| | M — market | 8 | 38 | correlated series that all turn in the same session | |
| | **total** | **58** | **194** | **77,929 ground-truth points** | |
|
|
| 1–12 series per chart. 8 panels on log axes (3 log-y, 3 log-x, 2 log-log). |
|
|
| Each chart isolates **one named failure**, declared in its spec before it is drawn — |
| A01 *"colour-based tracing that swaps identity at a crossing"*, A14 *"gap honesty"*, |
| C07 *"hatching is annotation"*, D10 *"a curvilinear coordinate system"*, M06 *"accumulated |
| identity error: no single crossing is hard, there are simply a great many"*. |
|
|
| ## Files |
|
|
| images/<ID>.png the figure, as an extractor receives it |
| truth/<ID>.truth.json the exact values used to draw it, plus axis_scales and |
| `printed` flags on labels that actually appear |
| spec/<ID>.spec.json what the chart tests, its difficulty level, and for the |
| M set the measured crossing schedule |
| metadata.jsonl one row per chart |
| index.json the same rows as a single array |
| |
| ## Suggested metric |
|
|
| score = series_recall x coverage x accuracy x mark_recall |
| |
| Kept as a product, not an average: recovering one of eight series perfectly must not read |
| as a good parse. Three properties matter more than the formula: |
|
|
| - **Pair series by shape, not by name** (Hungarian assignment), so a system cannot win on |
| labelling. |
| - **Error relative to each series' own range**, and compared in log10 space on a log axis — |
| otherwise a four-decade residual is dominated entirely by the top decade. |
| - **Compare nothing where the extractor declared a gap.** A declared absence is neither |
| credited as coverage nor bridged and charged as error. Saying "I could not see this" |
| has to be allowed to be the right answer. |
|
|
| Use RMS rather than median: a median hid a log-axis magnitude error at 12% where RMS |
| showed 22%. |
|
|
| ## Known limitations |
|
|
| - **C05** is drawn with no numeric y ticks, so its density values are not recoverable from |
| the image at all. It tests shape only. |
| - **A14 and C03** store values across a span wider than the figure can show (tails decaying |
| to ~4e-6 of the peak). A coverage measure taken against the stored array rather than |
| against visible ink will understate a correct parse on those two. |
| - **D10** is a Smith chart stored in reflection coefficient. A system answering in |
| normalised impedance is not wrong; the conversion is arithmetic an extractor should not |
| be expected to perform. |
| - Synthetic throughout. These charts are matplotlib output, so they carry none of the |
| compression artefacts, rotated scans, or hand-drawn annotation of a real document. They |
| measure numeric correctness, not robustness to bad inputs. |
|
|
