gdal_translate -of PNG test.tiff output.png

ERROR 6: PNG driver doesn't support 8 bands.  Must be 1 (grey), 2 (grey+alpha), 3 (rgb) or 4 (rgba) bands.

gdal_translate -of PNG -b 1 -b 2 -b 3 test.tiff output.png

gdal_translate -of PNG -expand gray -b 1 test.tiff output.png

ERROR 1: Error : band 1 has no color table

Magic: 0x4949 <little-endian> Version: 0x2a <ClassicTIFF>
Directory 0: offset 8 (0x8) next 0 (0)
ImageWidth (256) SHORT (3) 1<2604>
ImageLength (257) SHORT (3) 1<2233>
BitsPerSample (258) SHORT (3) 8<16 16 16 16 16 16 16 16>
Compression (259) SHORT (3) 1<1>
Photometric (262) SHORT (3) 1<1>
StripOffsets (273) LONG (4) 2233<18288 59952 101616 143280 184944 226608 268272 309936 351600 393264 434928 476592 518256 559920 601584 643248 684912 726576 768240 809904 851568 893232 934896 976560 ...>
SamplesPerPixel (277) SHORT (3) 1<8>
RowsPerStrip (278) SHORT (3) 1<1>
StripByteCounts (279) LONG (4) 2233<41664 41664 41664 41664 41664 41664 41664 41664 41664 41664 41664 41664 41664 41664 41664 41664 41664 41664 41664 41664 41664 41664 41664 41664 ...>
PlanarConfig (284) SHORT (3) 1<1>
ExtraSamples (338) SHORT (3) 7<0 0 0 0 0 0 0>
SampleFormat (339) SHORT (3) 8<1 1 1 1 1 1 1 1>
33550 (0x830e) DOUBLE (12) 3<2.20356e-06 2.20356e-06 0>
33922 (0x8482) DOUBLE (12) 6<0 0 0 -82.0121 27.3184 0>
34735 (0x87af) SHORT (3) 32<1 1 0 7 1024 0 1 2 1025 0 1 1 2048 0 1 4326 2049 34737 7 0 2054 0 1 9102 ...>
34736 (0x87b0) DOUBLE (12) 2<298.257 6.37814e+06>
34737 (0x87b1) ASCII (2) 8<WGS 84|>