Crop Regions

steps:
  - name: parse
    type: ai.parse
    with:
      input: "{{ input.document }}"
      parseMode: ocr

  - name: list-figures
    type: transform.script
    with:
      inputs:
        parsed: "{{ steps.parse.output }}"
      function: |
        function script(parsed: { pages: { pageIndex: number; width?: number; height?: number; layoutElements?: { type?: string; figureId?: string; boundingRegion?: { polygon?: { x?: number; y?: number }[]; unit?: string; pageIndex?: number } } }[] }[] }): { regions: { id: string; pageIndex: number; bbox: [number, number, number, number] }[] } {
          function normalizeBbox(
            xs: number[],
            ys: number[],
            unit: string | undefined,
            pageWidth: number,
            pageHeight: number
          ): [number, number, number, number] | null {
            if (!xs.length || pageWidth <= 0 || pageHeight <= 0) return null;
            const x0 = Math.min(...xs);
            const y0 = Math.min(...ys);
            const x1 = Math.max(...xs);
            const y1 = Math.max(...ys);
            if (unit === "normalized" || unit === undefined) {
              return [x0, y0, x1, y1];
            }
            return [x0 / pageWidth, y0 / pageHeight, x1 / pageWidth, y1 / pageHeight];
          }

          const regions: { id: string; pageIndex: number; bbox: [number, number, number, number] }[] = [];
          for (const page of parsed.pages ?? []) {
            const pageWidth = page.width ?? 0;
            const pageHeight = page.height ?? 0;
            for (const el of page.layoutElements ?? []) {
              if (el.type !== "figure") continue;
              const poly = el.boundingRegion?.polygon ?? [];
              const xs = poly.map((p) => p.x ?? 0);
              const ys = poly.map((p) => p.y ?? 0);
              const bbox = normalizeBbox(
                xs,
                ys,
                el.boundingRegion?.unit,
                pageWidth,
                pageHeight
              );
              if (!bbox) continue;
              regions.push({
                id: el.figureId ?? `fig${regions.length + 1}`,
                pageIndex: el.boundingRegion?.pageIndex ?? page.pageIndex,
                bbox,
              });
            }
          }
          return { regions };
        }

  - name: crop-figures
    type: transform.crop-regions
    with:
      input: "{{ input.document }}"
      regions: "{{ steps.list-figures.output.regions }}"