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

GeoloGISGeoloGIS Global Mapper UserPosts: 21Trusted User
edited February 21 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

  • SamRondeelSamRondeel Posts: 13
    Do you still have this problem? Can you send me a sample photo to try on my end?

    Thanks,
    Sam
  • GeoloGISGeoloGIS Global Mapper User Posts: 21Trusted 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_bobbmg_bob Global Mapper Programmer Posts: 1,834
    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
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