Problem loading NAIP 2016 scenes through QGIS STAC API Browser

[carmengg]

Hello. I'm trying to look at 2016 NAIP scenes over Santa Barbara County in CA using the STAC API Browser Plugin on QGIS. All the scenes I have loaded so far look washed out. Is there a fix for this? I need to visually select some places within the images but the incorrect coloring doesn't allow it. Thank for you help!

[TomAugspurger]

Thanks for the report! It looks like band 4 is being interpreted as "alpha" rather than "near-infrared". One of the items you shared was https://planetarycomputer.microsoft.com/api/stac/v1/collections/naip/items/ca_m_3412039_nw_10_.6_20160616_20161004. Calling gdalinfo shows

$ gdalinfo '/vsicurl/https://naipeuwest.blob.core.windows.net/naip/v002/ca/2016/ca_060cm_2016/34120/m_3412039_nw_10_h_20160616.tif'
Driver: GTiff/GeoTIFF
Files: /vsicurl/https://naipeuwest.blob.core.windows.net/naip/v002/ca/2016/ca_060cm_2016/34120/m_3412039_nw_10_h_20160616.tif
Size is 10400, 12330
Coordinate System is:
PROJCRS["NAD83 / UTM zone 10N",
    BASEGEOGCRS["NAD83",
        DATUM["North American Datum 1983",
            ELLIPSOID["GRS 1980",6378137,298.257222101,
                LENGTHUNIT["metre",1]]],
        PRIMEM["Greenwich",0,
            ANGLEUNIT["degree",0.0174532925199433]],
        ID["EPSG",4269]],
    CONVERSION["UTM zone 10N",
        METHOD["Transverse Mercator",
            ID["EPSG",9807]],
        PARAMETER["Latitude of natural origin",0,
            ANGLEUNIT["degree",0.0174532925199433],
            ID["EPSG",8801]],
        PARAMETER["Longitude of natural origin",-123,
            ANGLEUNIT["degree",0.0174532925199433],
            ID["EPSG",8802]],
        PARAMETER["Scale factor at natural origin",0.9996,
            SCALEUNIT["unity",1],
            ID["EPSG",8805]],
        PARAMETER["False easting",500000,
            LENGTHUNIT["metre",1],
            ID["EPSG",8806]],
        PARAMETER["False northing",0,
            LENGTHUNIT["metre",1],
            ID["EPSG",8807]]],
    CS[Cartesian,2],
        AXIS["(E)",east,
            ORDER[1],
            LENGTHUNIT["metre",1]],
        AXIS["(N)",north,
            ORDER[2],
            LENGTHUNIT["metre",1]],
    USAGE[
        SCOPE["Engineering survey, topographic mapping."],
        AREA["North America - between 126°W and 120°W - onshore and offshore. Canada - British Columbia; Northwest Territories; Yukon. United States (USA) - California; Oregon; Washington."],
        BBOX[30.54,-126,81.8,-119.99]],
    ID["EPSG",26910]]
Data axis to CRS axis mapping: 1,2
Origin = (752340.000000000000000,3821340.000000000000000)
Pixel Size = (0.600000000000000,-0.600000000000000)
Metadata:
  AREA_OR_POINT=Area
Image Structure Metadata:
  COMPRESSION=DEFLATE
  INTERLEAVE=PIXEL
  LAYOUT=COG
  PREDICTOR=2
Corner Coordinates:
Upper Left  (  752340.000, 3821340.000) (120d15' 5.70"W, 34d30'10.16"N)
Lower Left  (  752340.000, 3813942.000) (120d15'13.57"W, 34d26'10.26"N)
Upper Right (  758580.000, 3821340.000) (120d11' 1.29"W, 34d30' 4.59"N)
Lower Right (  758580.000, 3813942.000) (120d11' 9.35"W, 34d26' 4.70"N)
Center      (  755460.000, 3817641.000) (120d13' 7.48"W, 34d28' 7.44"N)
Band 1 Block=512x512 Type=Byte, ColorInterp=Red
  Overviews: 5200x6165, 2600x3082, 1300x1541, 650x770, 325x385
  Mask Flags: PER_DATASET ALPHA
  Overviews of mask band: 5200x6165, 2600x3082, 1300x1541, 650x770, 325x385
Band 2 Block=512x512 Type=Byte, ColorInterp=Green
  Overviews: 5200x6165, 2600x3082, 1300x1541, 650x770, 325x385
  Mask Flags: PER_DATASET ALPHA
  Overviews of mask band: 5200x6165, 2600x3082, 1300x1541, 650x770, 325x385
Band 3 Block=512x512 Type=Byte, ColorInterp=Blue
  Overviews: 5200x6165, 2600x3082, 1300x1541, 650x770, 325x385
  Mask Flags: PER_DATASET ALPHA
  Overviews of mask band: 5200x6165, 2600x3082, 1300x1541, 650x770, 325x385
Band 4 Block=512x512 Type=Byte, ColorInterp=Alpha
  Overviews: 5200x6165, 2600x3082, 1300x1541, 650x770, 325x385

Band 4 should be Band 4 Block=512x512 Type=Byte, ColorInterp=Undefined.

We've run into this before, but apparently didn't catch every instance. We'll look into it and let you know when it's fixed. In the meantime, if you have a way to disable the "alpha" band (Band 4) in QGIS things might look better.

[carmengg]

Thanks for looking into this! I disabled the alpha layer as transparency in QGIS and that fixed the visualization.