ndi.fun.doc.gene.chooseLevel

  CHOOSELEVEL - the coarsest pyramid level that still resolves a rectangle

    [BINSIZE, INFO] = ndi.fun.doc.gene.CHOOSELEVEL(T, RECTSOURCE, TARGETPIXELS)

    Given the level table T and a rectangle in SOURCE coordinates, returns
    the largest bin size whose rendering of that rectangle is still at
    least TARGETPIXELS across its longer side. Reading a finer level than
    the display can show costs bin-size-squared more tiles for pixels that
    are then thrown away; reading a coarser one loses detail the display
    could have shown.

    NOT NEEDED FOR NAPARI. napari's multiscale interface takes the whole
    ladder and picks a level itself from the shape ratios, so a napari
    viewer should hand it every level rather than choose one. This is for
    the callers that render a single image: a MATLAB figure, a thumbnail,
    an export, a tile server.

    Inputs:
    T            - the table from ndi.fun.doc.gene.levelTable
    RECTSOURCE   - [x0 y0 width height] in source coordinates (the GEF's
                   own x/y frame, the same frame cell centroids use)
    TARGETPIXELS - how many pixels the longer side should span, at least

    Outputs:
    BINSIZE - the chosen bin size, always one present in T
    INFO    - struct with fields:
                renderedWidth, renderedHeight - the rectangle's size in
                    bins at BINSIZE
                longSide      - max(renderedWidth, renderedHeight)
                metTarget     - false when even the finest level cannot
                    reach TARGETPIXELS, in which case the finest is
                    returned. Asking for more detail than the data holds is
                    a legitimate request with a definite answer; it is not
                    an error, but a caller that scales its display off the
                    result should know it happened.

    Example:
        T = ndi.fun.doc.gene.levelTable(S, pyrDoc);
        b = ndi.fun.doc.gene.chooseLevel(T, [3000 2000 4000 4000], 1024);

    See also: ndi.fun.doc.gene.levelTable, ndi.fun.doc.gene.readViewportBase