Error while loading map

  • Hi all,

    I have a raster map that I cannot load in QV7.

    Trying to activate this map with "Show in map", I receive a flashing blank screen for 1 or 2 sec than nothing and return to the Xplorer.

    I have tried the same map in different format (png, tiff, jpg)

    I have the same symptoms for all these format


    The TIFF file is about 2.5Gb

    The PNG file is about 2Gb

    The JPG file is about 500Mb


    My machine is equiped with W7 x64, 16Gb ram

    All these maps have been checked and can be opened correctly


    is there somewhere a logfile that may be checked for a detailled error ?

    For help, files are available on demand


    thx


    Jean-Michel

  • The TIFF file is about 2.5Gb

    The PNG file is about 2Gb

    The JPG file is about 500Mb

    Hi Jean-Michel,


    the file size does not indicate how large the map really is, all of these formats use compression. A couple of questions:


    - how many pixels does the map have, horizontal and vertical?

    - tif & png: which color mode, 8 bit, 24 bit or 32 bit?

    - tif: tiled? Internal overviews?

    Grüße
    Hans


    "The universal aptitude for inaptitude makes any human accomplishment an incredible miracle." (John Paul Stapp)

  • TIFF file

    54372pixels width

    42751 pixels height

    24 bits depth

    Compression LZW

    Tiled


    PNG file

    54372pixels width

    42751 pixels height

    24 bits depth


    JPG file

    54372pixels width

    42751 pixels height

    24 bits depth

    96dpi horizontal and vertical resolution

  • So your map expands to about 7 GB of data while loading. Given the map is already imported, right-click it in the X-Plorer list -> Style Maps -> General -> tick "Load partially...", and then try again. QV7 should be able to load at least the tiled tiff version of your map although i would suggest to reduce the color depth to 8 bits.


    In general, JPG is not a suitable format for large raster maps. My personal choice is tiled geotiff with 8bit color depth and internal overview pyramid, for imagery i prefer ECW.

    Grüße
    Hans


    "The universal aptitude for inaptitude makes any human accomplishment an incredible miracle." (John Paul Stapp)

    Edited once, last by Polarlys ().

  • Hello I have 9 grid tiles with a total of 5.5 gig as Tif I would like to load them in Q7 but I don't get any (not even individually) to load. I made a 1 gig out of it.

    I have produced ECW that works - quality too bad.

    I converted this to 8 bits. no success.


    Anyone know advice?


    Thank you Günter

  • following the advices of Polarlys, I've made some more tests . No more success than before ?(

    --> Right-click in the map in the X-Plorer list -> Style Maps -> General -> tick "Load partially..." : no success

    --> Reduce the color depth to 8 bits. : No more success


    Using ImageMagik, find here after a more accurate techspec of my TIF file

    May be somebody will find something strange or wrong


    Filename: D:\My Documents\2VM\Be 25k\Belgique_50.tiff

    Format: TIFF (Tagged Image File Format)

    Mime type: image/tiff

    Class: DirectClass

    Geometry: 54372x42751+0+0

    Units: PixelsPerInch

    Colorspace: sRGB

    Type: TrueColor

    Endianness: LSB

    Depth: 8-bit

    Channel depth:

    Red: 8-bit

    Green: 8-bit

    Blue: 8-bit

    Channel statistics:

    Pixels: 2324457372

    Red:

    min: 0 (0)

    max: 255 (1)

    mean: 229.917 (0.901635)

    median: 247 (0.968627)

    standard deviation: 48.9066 (0.191791)

    kurtosis: 6.22296

    skewness: -2.42095

    entropy: 0.39152

    Green:

    min: 0 (0)

    max: 255 (1)

    mean: 234.937 (0.92132)

    median: 247 (0.968627)

    standard deviation: 41.0257 (0.160885)

    kurtosis: 8.78267

    skewness: -2.74695

    entropy: 0.384043

    Blue:

    min: 0 (0)

    max: 255 (1)

    mean: 221.34 (0.868002)

    median: 247 (0.968627)

    standard deviation: 66.6199 (0.261255)

    kurtosis: 2.8444

    skewness: -1.98566

    entropy: 0.354516

    Image statistics:

    Overall:

    min: 0 (0)

    max: 255 (1)

    mean: 228.731 (0.896985)

    median: 247 (0.968627)

    standard deviation: 52.1841 (0.204643)

    kurtosis: 5.68258

    skewness: -2.42632

    entropy: 0.376693

    Rendering intent: Perceptual

    Gamma: 0.454545

    Chromaticity:

    red primary: (0.64,0.33)

    green primary: (0.3,0.6)

    blue primary: (0.15,0.06)

    white point: (0.3127,0.329)

    Matte color: grey74

    Background color: white

    Border color: srgb(223,223,223)

    Transparent color: none

    Interlace: None

    Intensity: Undefined

    Compose: Over

    Page geometry: 54372x42751+0+0

    Dispose: Undefined

    Iterations: 0

    Compression: LZW

    Orientation: TopLeft

    Properties:

    date:create: 2021-02-09T18:35:01+00:00

    date:modify: 2021-02-09T17:22:14+00:00

    signature: ca4d6f306a56bee445f2473bdd5f4bdb4a3dbe5db762f5136517e5bff4eece9d

    tiff:alpha: unspecified

    tiff:endian: lsb

    tiff:photometric: RGB

    tiff:rows-per-strip: 1

    Artifacts:

    verbose: true

    Tainted: False

    Filesize: 2.38263GiB

    Number pixels: 2.32446G

    Pixels per second: 5.67873MP

    User time: 133.896u

    Elapsed time: 6:50.326

    Version: ImageMagick 7.0.11-2 Q16 x64 2021-02-28 https://imagemagick.org

  • To Guenter and jmvmla,

    your maps are in a unpleasent format. You need some kind of tiling format to show the map in QV7.


    For an export use tiled tiff or ecw. Hans prefers tiled tiff, i prefer ecw. If you use QVX, than also mbtiles are possible ( i think this did not work in QV7).


    I like ecw, but for these normal maps you have to take a look at the compression ratio. In Global Mapper i use a ratio of 2 or 3 and i am pleased with this. For Sat-Images you can choose a higher compression.


    Greetigs

    Denis