Conversion to PNG or JPG results in a black image

[tgd]

I have used gdal_translate to convert tif images to png and jpeg and the result is a black image. I never had a problem with RGB tifs. The problem I am facing affects only grayscale images. Expanding these images to RGB also fails.

This is one of the files in my project: ​http://aristeia.ha.uth.gr/images/1.tif

This is the correct result using photoshop (which of course strips all geotagging): ​http://aristeia.ha.uth.gr/images/1.png

While gdal gives me this: ​http://aristeia.ha.uth.gr/images/2.png

As there a few hundrends of such images in the QGIS project, converting them in photoshop and georeferencing them again is not an option.

Probably this error is connected with Ticket #5761 "gdalwarp zeroes all alpha pixels from grey+alpha image".

[tgd]

Original TIF file.

[Jukka Rahkonen]

It would be better to open discussion on gdal-dev mailing list ans create tickets only after the issue is confirmed and located.

I can not reproduce the error with GDAL 2.0-dev on Windows 7, 64 bit, with GDAL binaries from gisinternals.com/sdk. Both png and jpg versions show the drawing just fine.

gdal_translate -of png Amorgos_Minoa_1_FINAL.tif bug1.png
gdal_translate -of jpeg Amorgos_Minoa_1_FINAL.tif bug1.jpg

However, I do not understand what you talk about greyscale images. Did you attach right samples? See the gdalinfo report of Amorgos_Minoa_1_FINAL.tif:

Band 1 Block=1394x1035 Type=Byte, ColorInterp=Red
  Mask Flags: PER_DATASET ALPHA
Band 2 Block=1394x1035 Type=Byte, ColorInterp=Green
  Mask Flags: PER_DATASET ALPHA
Band 3 Block=1394x1035 Type=Byte, ColorInterp=Blue
  Mask Flags: PER_DATASET ALPHA
Band 4 Block=1394x1035 Type=Byte, ColorInterp=Alpha

[Even Rouault]

Closing. Doesn't seem there's actually a problem. Reopen if you have more elements to provide.