ecw Background transparency

[Anonymous]

Hi Guys,

Need some help, been searching and searching and didn't get a proper help on this.

When importing an .ecw image into civil3d and when doing the background transparency the all photo comes off (not only the white edges as expected).

Image was exported from Global Mapper.

[Pointdump]

Hi Hugo,

Welcome to the Autodesk Forums.
More details please. How are you importing the ECW into Civil 3D? Is there any rotation involved? A screen shot of where you're setting the transparency would be helpful. And can you post the ECW? This forum will accept files up to 71 MB. You might have to zip first.
Dave

[Anonymous]

Hi Dave,

ecw comes from a drone orthophoto, inserting with mapiinsert into the correct location, to set the transparency is in the normal command, the tif works but the ecw not, the files are up to 140mb.

[Pointdump]

Hugo,
Looks like you've already discovered that converting the ECW to a TIF solves the problem. Another possible source of problems is the irregular shape of your images. With drone photos there's not much you can do about that.

For posting files larger than 71MB on this Forum you can link to WeTransfer, DropBox, Autodesk Drive, etc.
Dave

[Anonymous]

Didn't solve the problem yet.

Using global mapper when exporting the orthophoto in tif i can make background transparency in civil3d, but when exporting in ecw i cant make the background transparency in civil3d.

The idea is exactly to have the various photos in ecw because the tif files are to heavy to work on civil3d.

For instance the same photo in tif is 1.4gb and in ecw is 160mb, the quality is as good but the problem is i cant execute the background transparency.

https://we.tl/t-QfwcPxh9bb

[Pointdump]

Hugo,

Thanks for posting your images.
I tried just now using FDO (MAPCONNECT) and setting transparency, but this is the best I could do.
Dave

[Anonymous]

Hi Dave,

I also get there.

I wonder if i can find why I'm not getting to a proper background transparency. Is this a ecw problem? 

[Pointdump]

Hugo,
"Is this a ecw problem?"
I think it's more a problem with the shape of the images. And it's not just Civil 3D, I get the same thing in QGIS.
Dave

[AEC_Cadd]

I use Raster Design to crop the ecw file to get of the border.

[Pointdump]

@AEC_Cadd,
If you zoom in you see photo "pieces". Will Raster Design crop to the "main" image?
Dave

[AEC_Cadd]

I use Raster Design to trim out any area that is white and then put the trimmed photo on top of the previous one.

Sometimes I need to trim both photos if it is necessary. There are a lot of options in Raster Design to crop a photo.

[Pointdump]

@AEC_Cadd,
I tried just now cropping in Raster Design. I see nothing "automatic". You have to manually trace a crop line. Then you can only save in TIF format, not ECW as Hugo wanted. Turns a 172MB ECW image into a 7GB TIF.
Dave

[huynhphanson71 · Accepted solution]

Hi @Anonymous 

I suggest u should use command "Imageclip" , I think it will solve your problem

[CivilFlow]

@huynhphanson71 

I had a .ecw v2 which had a transparency band but when toggling transparency on in C3D there were small pixels around the irregular clip of the Ortho that persisted to show around the edges. Most frustrating since this issue does “not” occur in ArcGIS Pro.

Anyway, I tried exporting from Geocompressor new versions of the .ecw with different backgrounds (white and black assigned as the transparency band), but no luck until I can across your tip about using an image clip. Problem solved.

I wonder if this issue would persist in the latest version 3 of .ecw, but sadly it still is “not” supported 😒 Knowing how popular UAS imagery is and all the documented issues around large size tif files in C3D, you would think Autodesk would recognize these compressed image formats as a real viable work-a-round. the solution is here in .ecw. 2.5GB drone image compressed to 80MB...no problem. All they have to do is support it!!

end rant /