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export a clipped georeferenced image


Openantics

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i have successfully imported and clipped my georeferenced image, and need to know:

 

is it possible to export the clipped image as a georeferenced image? that is, will c3d generate a TIFF cut to the clip boundry and include metadata file (worldfile) outlining the new bounding coordinates?

 

my goal is to load the clipped image into GIS software for additional analysis but the coordinate system has to come along and hopefully just the small area i clipped!

 

thank you!

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Not Civil3D alone, with Raster Design add-on it will create the world file. However if you follow the correct order of things , as listed here, you can create the world file using notepad or any text editor and save as twf.

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Not Civil3D alone, with Raster Design add-on it will create the world file. However if you follow the correct order of things , as listed here, you can create the world file using notepad or any text editor and save as twf.

 

thank you for the link to both the add-on and wiki article. I have limited success in the past altering/creating worldfiles and just as well let a machine generate it! With that said, how do i locate the coordinates of my clipped file, which i created by eye? The properties box seems to give the insertion point only for the larger, attached image. Where do the properties for the clipped image reside??

 

thanks

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Select the image and do a "list" on it, it will return the 4 corners of the boundary, rotation and scale, everything you need for the world file.

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Select the image and do a "list" on it, it will return the 4 corners of the boundary, rotation and scale, everything you need for the world file.

 

there it is, thanks. i assume the coordinates for my clipped image as given by the LIST command, are the 'outside' corners of the object not the pixel center as the .tfw will require. easy to calculate, but still unclear how to apply this data to the image, then save!

 

thank you for your time.

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Yes the coordinates are the out side corners of the pixels. However you can not save the clip image as a new image file with out Raster Design or another raster editing application. To create the world file you would just follow the sample in the link provided creating a text file and save it with the same name as the image file with the extension of twf in the same folder as the image file.

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  • 4 weeks later...
However you can not save the clip image as a new image file with out Raster Design or another raster editing application

Well, he can, definitely and for free (I do it very often, without problems).

 

He only needs to print the clipped image to the virtual Autodesk TIFF printer (added in Plotter Manager), then imports the brand new TIFF in the right place of the map (command _ALIGN), finally he automatically generates the new Worldfile with this tool.

 

P.S.

By the way, dear Openantics, there's a couple of opensource GIS tools saving (directly) cropped geo-images as new Geotiffs...

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Well, he can, definitely and for free (I do it very often, without problems).

 

He only needs to print the clipped image to the virtual Autodesk TIFF printer (added in Plotter Manager), then imports the brand new TIFF in the right place of the map (command _ALIGN), finally he automatically generates the new Worldfile with this tool.

 

P.S.

By the way, dear Openantics, there's a couple of opensource GIS tools saving (directly) cropped geo-images as new Geotiffs...

 

 

very cool - thank you for the reply. All the cropping/GIS tools i have tried leave a large white background so maybe this is it. i am new to GIS tools, so dont suppose you have a link to search "GIS tools" or even better, names of this opensource GIS tools that save cropped geotiffs?!

 

tia!

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i was able to print my cropped tif, but it still leaves a large white background i think representative of the original image dimensions. maybe this get 'cut out' when i generate the worldfile? is it possible to create/clip/save an image with a worldfile of just the cropped image?

 

regards

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Well, he can, definitely and for free (I do it very often, without problems).

 

He only needs to print the clipped image to the virtual Autodesk TIFF printer (added in Plotter Manager), then imports the brand new TIFF in the right place of the map (command _ALIGN), finally he automatically generates the new Worldfile with this tool.

..

 

Great tip on using the TFF printer, didn't think about that. :oops:

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it still leaves a large white background

You can easily crop the new image without margins or background, by means of any graphic editor (my preferred one is Irfanview).

 

Then in Autocad you insert that clean image, and align it according to your map.

 

I advice you to choose a good compromise size/resolution when you print to the virtual TIFF printer.

 

;)

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