Question

PNG bit depth

  • 9 January 2014
  • 3 replies
  • 12 views

Hi,

 

 

I have a process that converts a DWG to PNG tiles.

The last transfomer before the writer is a RasterBandPropertiesExtractor to check what will be written. This shows that each tile is RGB24 bit (red8, green8, blue8) also the tiles that are completely filled with background (255,255,255).

 

But when the PNG tiles are written the tiles with only background are converted to a 1bit image instead of a 24bit image.

 

 

Is there a way to force RGB24 tiles like you can with the tiff writer?

 

 

Regards,

 

Rob

3 replies

Userlevel 3
Badge +13
Hi Rob

 

This seems to work for me but I "made" the data by reading a PNG that is all background. Not sure how else to create it.  Are you definitely using the PNGRASTER writer and not the PNG writer (which is the old rasterizer writer)?  Does the data have an alpha band?
Hi Ken,

 

 

The writer I'm using says "PNGRASTER" in the navigator.

 

When using the RasterBandPropertiesExtractor I can see that there is no alpha band in the process as the ImageRasterizer has RGB24 as Interpretation Type.

 

 

Hope I'm missing something obvious.

 

 

Solved by Ken

 

 

Removing the optimizatin in the writer did the trick.

 

 

Thanks

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