Overviews Read Incorrectly when Per Dataset Masks Present

[notthatbreezy]

Describe the bug

When a COG has per dataset masks the masks can be read as overviews incorrectly.

To Reproduce

Provide as able:

• Use the COG in the attached zip file
• Run the following code (create a rastersource, iterate over overviews to get band counts)

import geotrellis.raster.geotiff.GeoTiffRasterSource
val s = "<path to attached tiff>"
GeoTiffRasterSource(s).tiff.overviews.map(_.bandCount)

On my local machine this yielded the following:

scala> val s = "/mnt/c/Users/chris/projects/imagery/per-dataset-mask.tif"
s: String = /mnt/c/Users/chris/projects/imagery/per-dataset-mask.tif

scala> val rasterSource = GeoTiffRasterSource(s)
rasterSource: geotrellis.raster.geotiff.GeoTiffRasterSource = GeoTiffRasterSource(/mnt/c/Users/chris/projects/imagery/per-dataset-mask.tif)

scala> rasterSource.tiff.overviews.map(_.bandCount)
res6: List[Int] = List(1, 3, 1)

Showing 3 overviews with 1, 3, and 1 bands respectively.

Meanwhile gdalinfo shows there is only a single overview:

root@764d7618786e:/tmp# gdalinfo per-dataset-mask.tif
Driver: GTiff/GeoTIFF
Files: per-dataset-mask.tif
Size is 1024, 1024
Coordinate System is:
<ommitted>
Band 1 Block=512x512 Type=Byte, ColorInterp=Red
  Overviews: 512x512
  Mask Flags: PER_DATASET
  Overviews of mask band: 512x512
Band 2 Block=512x512 Type=Byte, ColorInterp=Green
  Overviews: 512x512
  Mask Flags: PER_DATASET
  Overviews of mask band: 512x512
Band 3 Block=512x512 Type=Byte, ColorInterp=Blue
  Overviews: 512x512
  Mask Flags: PER_DATASET
  Overviews of mask band: 512x512

Expected behavior

Only overviews are returned, masks are not returned

Additional context

Based on the documentation in gdal I suspect the raster masks are getting read as overviews because they are also put in the IFD, but do not represent lower resolution images.

[notthatbreezy]

per-dataset-mask.zip

Here is a tiff used to reproduce the issue