Convert GeoTIFF to KMZ Raster slow down

[MrKyle]

I am running into something unusual when converting GeoTIFF files to KMZ, namely GeoTIFF files with a color depth higher than 2 colors (1bpp). For color images the process will be extremely slow compared to converting black and white images. By extremely slow I mean it can take over an hour or more to convert the color image versus a couple mins for the black and white.

I run the Batch Convert/Reproject...

Here are the settings I need to use:
- Default Sample Spacing
- Format: PNG (256 Color Palette)

Then I check the following from the list:
- Automatically Grid (Super Overlays)
- Add Watermark Image (use a simple text image with black lettering and make the white background transparent)
The rest are the defaults from what I remember:
- Force Square Pixels in Output
- Convert to Grayscale
- Make Background Pixels Transparent
- Show Batch Conversion Progress


I am hoping there's a fix or setting when converting high(er) color depth images so that they process as rapidly as black/white images.

I have a feeling the super overlay process may be a factor as well as the PNG, but I need to use these to have a clean, quick loading KMZ in GE. For now, I need to take extra time to downsample color images to black/white & greyscale.

I'd be happy to supply two different images (b/w & color) for testing if you'd like.

Thanks for any help!

Kyle

[global_mapper]

Kyle,

That is odd, I wouldn't expect any significant different between the two, assuming they both start with the same pixel dimensions. If you can provide the sample files I can take a look.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

[MrKyle]

Mike.

Thank you very much. We finally procured our v11 license and tested out your update. The images process much faster now!


Kyle

[MrKyle]

Is there a limit to the:
DPI
Dimensions
Color Depth
for a fast conversion?

I'm trying to convert a rather large TIF and am experiencing a similar slow down as before. I would expect some since it is a larger file, but not back to a crawl in the processing. Here are the file's specs:
300 DPI
10800 x 7200 pixels
16.7 million colors (24bpp)
34 mb file size
LZW compression

Thank you for the great help!

[global_mapper]

The slowdown that was occurring was happening because the image was rotated and the cache was not large enough to efficiently handle a rotated image of that large of size. Do you have a 64-bit machine available to you? In the 64-bit version of Global Mapper the in-memory cache for TIFF files is much larger and would be able to handle larger, significantly rotated images more efficiently than the 32-bit version which has less memory available to it.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

[MrKyle]

Thanks Mike.

Alas I do not. I did some trials reducing the pixel size by about 10% and it looks like downgrading by half to 5000 x 3333 for this type of image was a good size for my memory cache to speed through the conversion. I guess I'll have to go with this until we can get some 64-bit OS's installed.

Thanks!