pub fn gray_page(
doc: &PdfDocument,
page: usize,
dpi: u32,
) -> Result<(u32, u32, Vec<u8>)>Expand description
Render a page to Gray8 bytes at the given dpi: (width, height, data),
row-major, top-left origin, 0 is black.
The RGBA output of PdfDocument::render_page composited over white and
converted to ITU-R BT.601 luma. The ONE conversion: the vision layer’s Gray8
path calls this, and the dump’s image arm reads its bytes without the
vision feature (#574).