I did some checking and it does seem that Spatial needs to upgrade its ECW support for the alpha channel. I found an example and indeed the background displays transparently in more recent versions of MapInfo Pro but with a black background in Spatial. As I said earlier, Spatial already can support alpha channel but without a code change, processing the alpha channel information needs special handling.
We are also considering using more of the same code that the Raster module uses in MapInfo Pro in Spatial. We already share the code for rendering MRRs but we also do this on Linux, which is a Spatial requirement.
Note that in MapInfo Pro, if you disable ECW handling in the Options, Raster and revert it back to the traditional raster ecw handler, MapInfo Pro renders this image with the black background. So it definitely is working due to work that was done in that module.
Thanks for raising this!
Generically, there is nothing you can do. However, you can still provide a raster override to set the transparent color. I tried this with my example but because there was real black in the image itself, those pixels became transparent and that was not desirable. This may not be the case in your images and may be a suitable workaround.
To try this, try the layer style in Pro and choose pick the transparent color. If there is not other black in the image it should look fine.
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Eric Blasenheim
Spectrum Spatial Technical Product Manager
Troy, NY
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Original Message:
Sent: 09-06-2019 09:30
From: Eric Blasenheim
Subject: Black Border in SSA aerial but not in Mapinfo
One more point. If the goal here is to make a single color (black) disappear, that can be done with the transparent color option without alpha channel support.
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Eric Blasenheim
Spectrum Spatial Technical Product Manager
Troy, NY
Original Message:
Sent: 09-06-2019 09:28
From: Eric Blasenheim
Subject: Black Border in SSA aerial but not in Mapinfo
The image you shared showing the coordsys clause in the tab file for the ecw is what I wanted to see. It does look normal. Very often, raster images can have what we call an "affine" extension to the coordinate system but that does not seem to be the case here.
I am checking with colleagues to see who has an ecw with alpha channel to test.
Spatial has supported alpha channel for a very long time but because Mapinfo Pro did not support it, we did not see many examples from customers. ECW is rendered using the native libraries and there may be a difference there. If you have a simple example or have sent this to support we can verify on the Spatial end.
Again, the Analyst application has nothing to do with this as all the rendering is handled in the underlying Spectrum Spatial services.
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Eric Blasenheim
Spectrum Spatial Technical Product Manager
Troy, NY
Original Message:
Sent: 09-04-2019 20:36
From: Kieran McGowan
Subject: Black Border in SSA aerial but not in Mapinfo
Thank you for the followup gentlemen.
@Eric, yes this is a seamless layer using the following documented method to add approx 10 ecw mosaics(townships) http://support.pitneybowes.com/SearchArticles/VFP05_KnowledgeWithSidebarHowTo?id=kA1800000008a8jCAA&popup=false;&lang=en_US
The seamless layers .tab file makes no reference of cordSys as far as i can see, however each of the 10 township .tab files show Earth Projection as shown in attached. (single_town_tab,seamless_layer_tab)
It doesn't look like a seamless layer issue as uploading all the tabs/images individually i also see the black border. Preforming Johns test, adding bing aerial as the base layer and then the townships also looks fine in mapinfo. Projection also looks correct. (see screenshot from MI and SM)
The ecw files for the towns were originally in GDA 94, i used FME to reproject to EPSG3857 just so that SSA would not have to do this 'on-the-fly' and impact performance. Using the raw GDA94 imagery and leaving it to SSA to reproject works well but defeats the purpose. Perhaps my understanding is incorrect, but by adding an alpha channel to each of my township imagery before reprojecting it, the imagery remains square and the new 'empty' space is automatically considered as no data. which MI seems to identify but SSA doesn't.
Are you saying that its not possible or at least difficult to have business maps reprojected without showing black borders? It seems the only way i can get around this is merging the 'rural' and 'townships' into one mosiac which i was trying to avoid. my base understanding for this process is if it works in MI it should in SSA.
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Kieran McGowan
Knowledge Community Shared Account
Shelton CT
Original Message:
Sent: 09-04-2019 10:46
From: John Ievers
Subject: Black Border in SSA aerial but not in Mapinfo
SSA is less forgiving with projections. The base mapping will define the projection in a Project/map config.
If you have re-projected your aerial imagery then the likelihood is that it is no longer "square" with the base mapping and you will get black borders.
Try opening your imagery in MapInfo with Bing or GeoMap as a base and you should see a similar effect, if not worse!
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John Ievers
CDR Group
Hope Valley, United Kingdom
Original Message:
Sent: 09-03-2019 21:07
From: Kieran McGowan
Subject: Black Border in SSA aerial but not in Mapinfo
Hi All,
Hopefully this is an easy one. I'm getting a black border/collar/edge around a 'seamless layer' in SSA(2018.2.0) when placed on top of another business map.
Before uploading the imagery(ECW) the layers look fine in Mapinfo(17.0.3) with no black border. (see attached png)
I'm basically putting high resolution township imagery over a rural aerial mosiac.
Before uploading i've added an alpha band and reprojected to EPSG:3857 to work better in SSA, then uploaded the rural and township(seamless layer) separately. I'm not sure why it looks perfect in mapinfo and not ssa so any help is appreciated.
KR
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Kieran McGowan
GIS Officer
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