Automatic Rescaling

[vincentsarago]

in rio-tiler https://github.com/cogeotiff/rio-tiler/blob/6d71e7d380cd815b8f65a1917653769d882c2aa6/rio_tiler/models.py#L732C10-L758

we automatically rescale the data IF ONLY we know the output format (e.g. PNG) will not work with the Image datatype (e.g. int32). We will rescale the array using either Min/Max from COG metadata or Datatype range (starting with 5.0, rio-tiler will also use STAC statistics extension).

This is really useful to make sure we always return images, and if using statistics, to return meaningful image. This could be extended to always rescale the image

form

titiler/src/titiler/core/titiler/core/factory.py

Lines 553 to 560 in 047453f

	if rescale:
	image.rescale(rescale)
	if color_formula:
	image.apply_color_formula(color_formula)
	if cmap := colormap or dst_colormap:
	image = image.apply_colormap(cmap)

to something like

if image.dataset_statistics and not (rescale or color_formula or colormap or dst_colormap):
    image.rescale(img.dataset_statistics)
else:
    if rescale:
        image.rescale(rescale)

    if color_formula:
        image.apply_color_formula(color_formula)

    if cmap := colormap or dst_colormap:
        image = image.apply_colormap(cmap)

cc @matthewhanson