Global Mapper v25.0

User controlled Contrast Linear Min/Max stretch

apogee
apogee Global Mapper User
edited July 2010 in Suggestion Box
Hi guys/girls,

We are trying to use global mapper(nice product). The current issue we are encountering is the colour/contrast adjustment. The Linear Min/Max stretch that is produced in Global Mapper does not match the Linear Min/Max produced in either Envi or Ossim Image Linker. Could you implement an additional Linear Min/Max contrast stretch that takes user input either as a slidebar or input value to give the user more control.

I have attached an example of the difference between globalmapper auto min/max contrast stretch and ossim image linker auto min/max contrast stretch.

Kind Regards,
Nicholas

Comments

  • global_mapper
    global_mapper Administrator
    edited July 2010
    Nicholas,

    It almost looks like there is an alpha channel present in your image that is causing the image colors to blend with the background color, which defaults to yellow. If you change your View->Background Color to say black does that affect the image?

    The base min/max stretch is pretty straight-forward so I'm not sure what options would apply there, but you can restrict the range of each color band separately on the Color Grade tab. Perhaps this could help?

    If you still have trouble and want to post an actual sample image I can take a look.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com