Global Mapper 19 does not properly support INSPIRE-compliant JPEG2000 orthoimagery

GeoloGIS
GeoloGIS Global Mapper UserTrusted User
edited February 2018 in Bug Report
According to the European Commission's INSPIRE Technical Guidelines (v2013.12.10, page 140),
"JPEG 2000 allows defining opacity channel on more than 1 bit to have a scale of transparency. In our case, we‘re just interested in full transparency and full opacity. So, within the scope of INSPIRE, it is recommended to code it on only 1 bit (0= transparent, 1=opaque)
Recommendation 38:In the case of an opacity channel, the bit depth should be 1-bit"

We have thousands of orthoimagery files which are fully INSPIRE-compliant, yet Global Mapper v19.0 opens such files but displays them as fully transparent (and thus, nothing is to be seen), probably due to misinterpreting their 1-bit alpha channel.

Other JPEG2000 software (e.g. the free Kakadu kdu_show) have no such issue.

Comments

  • Do you still have this problem? Can you send me a sample photo to try on my end?

    Thanks,
    Sam
  • GeoloGIS
    GeoloGIS Global Mapper User Trusted User
    Exemple file here: https://nofile.io/f/pBb3Nq8K8RD/test.jp2
    (2MB sample imagery with 8,8,8,1-bit per component i.e. RGB + 1-bit alpha)

    GM 19.1 = bad interpretation
    Kdu_show = correct interpretation
    Adobe Photoshop = correct interpretation

    INSPIRE Data Specification on Orthoimagery – Technical Guidelines:
    https://inspire.ec.europa.eu/id/document/tg/oi


  • bmg_bob
    bmg_bob Global Mapper Programmer
    Hello,

    I loaded your test file into the latest Global Mapper 20 beta, and it is not transparent.  See attached screen capture (note that I also loaded some additional world map data to confirm that the JP2 image is not transparent.)



    Cheers,
    Bob