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mikedufty

808 post(s)
#05-Nov-18 07:23

Does anyone know if there is a way to make a transparent compressed image in Manifold 9.

I have an 8GB big TIFF aerial with transparent parts. Manifold 9 has done a good job of exporting it to a much more manageable ecw, but has replaced all the transparent parts with black.

This is becoming an increasingly common problem with the prevalance of small patches of imagery from drones that we want to overlay on older imagery. Can get by with uncompressed for small stuff but 8GB files are a bit too much.

adamw


8,204 post(s)
#05-Nov-18 08:10

This is a licensing issue.

We can currently read any ECW / JPEG2K / SID, and can export unlimited size ECW / JPEG2K but cannot export the latest versions of these formats - no support for transparency or 16-bit color.

mikedufty

808 post(s)
#05-Nov-18 08:20

Thanks,

It would be a nice feature if you could get it licenced.

Dimitri

5,082 post(s)
#05-Nov-18 10:38

Getting it licensed is something you would do, since the ability to write ECW Version 3 is a standard product from Hexagon. It's part of the Provider Suite of their Power Portfolio product.

Manifold's role would be to support it if you bought a license from Hexagon.

Are you really willing to spend that much money to write ECW Version 3, given that you can write unlimited size ECW Version 2 right now?

I ask because while it would be easy enough for Manifold to add support for such things, it doesn't seem to make sense to do so if nobody at all is willing to spend what Hexagon requires to go to Version 3 from Version 2.

For background on this and the licenses Manifold provides/uses, see the ECW topic.

mikedufty

808 post(s)
#07-Nov-18 05:53

No I don't want to pay for it, I would like it included for free in Manifold. Please?

The help topic you linked doesn't mention that transparent pixels do seem to be supported in the later ecw format.

Is there another compressed or linkable format with transparency that is more accessible?

danb


1,664 post(s)
#07-Nov-18 07:25

I wonder what SDK Global Mapper uses for its ECW exports? My main reason for initially buying GM was to compress to ECW with transparent pixels for irregular image data as this was always something I missed in M8. Would the ability to create JPEG2000 images with transparent void pixels be a useful alternative?


Landsystems Ltd ... Know your land | www.landsystems.co.nz

mikedufty

808 post(s)
#08-Nov-18 01:47

I think jpeg 2000 with transparent pixels would be a useful alternative, but have no idea if the format supports that.

I think I tried it and it didn't work currently, but can't recall if I tried in M9 or just M8.

Currently being pushed towards using QGIS instead since you can just link the tiff files.

My work around in Manifold is to overlay the transparent tiff on older imagery and make a new rectangular combined image to ecw, but it is a bit of pain especially with very large images.

adamw


8,204 post(s)
#08-Nov-18 14:25

JPEG 2000 does support transparent pixels (although clearly describing the relevant channel as alpha has historically been an issue in many libraries).

We will see what we can do.

If you are interested in JPEG 2000 / ECW files with transparent pixels, please indicate such interest by dropping a suggestion, suggestions influence what we are planning to do and when.

danb


1,664 post(s)
#08-Nov-18 18:09

Hi Adam,

I was suggesting JPEG2000 as an open alternative to ECW with similar performance. I have for many versions of Global Mapper exported irregular images setting 'Make Background (Void) Pixels Transparent' (see Image 1).

I just tried this again after reading your post using Global Mapper 15 (20 is the current version). And created a JPEG2000 image with transparent background so perhaps they have extended the original specification?

These import fine into M8 (see Image 2) but linking or importing into M9 9.0.168.4 seems to have an issue (see Image 3).

Please let me know if you want me to upload the image in question to tech to have a look at.

PS It also opens fine with transparency in QGIS latest, SAGA 6.4 and ArcMap 10.4 (thought the colours are a bit wonky ... looks like the band arrangement is not correct).

Attachments:
Image 1.jpg
Image 2.jpg
Image 3.jpg


Landsystems Ltd ... Know your land | www.landsystems.co.nz

danb


1,664 post(s)
#08-Nov-18 18:32

I also made a more extreme JPEG2000 example shown here in M8.

Attachments:
Sample 2.jpg


Landsystems Ltd ... Know your land | www.landsystems.co.nz

adamw


8,204 post(s)
#09-Nov-18 08:02

Please let me know if you want me to upload the image in question to tech to have a look at.

Yes, please do this. From your images it looks like 9 is misinterpreting the data in that particular file, we'd definitely want to understand why and fix it.

danb


1,664 post(s)
#09-Nov-18 18:15

I have just sent the sample images to tech.


Landsystems Ltd ... Know your land | www.landsystems.co.nz

Dimitri

5,082 post(s)
#08-Nov-18 19:07

since you can just link the tiff files.

You can just link the tiff files in 9 as well. But then your data is still in TIFF.

I just use .map files for storage. They are way faster. Link one in with zero speed penalty. I don't particularly care about the size of the file since what I want is speed. Since you can nest linked .map files with no speed penalty, you can keep very large amounts of data in map files without any one of those map files becoming too big.l

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