MapInfo Pro

Currently PNG images used as custom symbols in MapInfo Pro or Spectrum Spatial Analyst don't display correctly. White or near-white pixels in the original PNG image display incorrectly as transparent. This makes maps using custom PNG symbols look very scrappy and difficult to read. To avoid the unwanted transparency I'm having to manually edit the PNG images to change any white pixels to another color e.g. yellow however I want them to be white, not yellow.

Hi Colin, Can you send us an example by messaging me the file? Spectrum does handle PNG files as 32 bit. MapInfoPro as 24 bit. What is the transparency settings on the PNG that is being used? Can you also attach your image so we can have are team test this for you.

?Colin,

I think I know what is going on here but an example PNG might be required. Spectrum Spatial supports 32-bit PNG which means that there is a RGB and translucency channel called the Alpha channel. You may already know this but just for clarity.

MapInfo Pro does not yet support this channel but rather converts the PNG to 24-bit (just RGB). But the server would be looking at and respecting the values in the Alpha channel. Presumably if all those bits were set to opaque then there would be no difference in the display. So I believe that the image must have something there  and Spatial is using that whilst MapInfo Pro is ignoring it.

32-bit support will be added to MapInfo Pro in the next release, I believe.

You can raise a case with support and send them the image or we can figure out some other way and I can check it  or report back if there is a different problem.

Hi Matt, thanks for the reply. See attached one version in .png and one in.tif format. In my testing both have similar issues when displaying in MapInfo pro (v16). I’ve tried saving the PNG as both 32 bit and 24 bit and the problem remains. Here is a close up zoom of the image in an image editor. Notice the opaque white pixels in the middle and the transparent pixels around the outside. [cid:image002.jpg@01D332C7.1F08FDC0] Now this is how the image appears in MapInfo Pro when used as a custom symbol. To illustrate the point I’ve overlayed one over a yellow polygon and one on its own. The centre of the teapot should be white but it is clearly taking on the colour of whatever is underneath. Notice also the grey outline around the symbol that shouldn’t be there. [cid:image006.png@01D332C5.59D2A700] An now here is what it looks like when there are many points close together… [cid:image004.png@01D332C6.183646C0] Now here is a similar symbol in SSA. The toilet symbol is ordered above all the other layers however the layers below are clearly showing through the white part of the symbol: [cid:image007.png@01D332C7.1F08FDC0] I’ve invested a lot of time in trying to get this to work so it would be great to have a solution to this problem. Thanks for your help. Colin Broughton | GIS Officer (Wednesday & Thursday) Nillumbik Shire Council | Civic Drive (PO Box 476) Greensborough Victoria 3088 9433 3331 | colin.broughton@nillumbik.vic.gov.au<mailto:colin.broughton@nillumbik.vic.gov.au>

Hi @Colin Broughton? ? , I have faced the same issue. Instead of struggling with Image Bitrate conversion. I have chosen the PNG which is already 24 Bit. whenever we change the bit rate of highresolution PNG we can expect the white opaque. I'm really looking forward to the solution for this

Support for alpha channel in PNG images is very much needed :-) Maps will look so much better with correct transparency, instead of the jagged edges we get now.