Cloud Removal - Revision history

Bew at 22:12, 9 March 2007

2007-03-09T22:12:04Z

← Older revision		Revision as of 22:12, 9 March 2007
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	The clouds have gone but their shadows are still there. Roads suddenly end in a green		The clouds have gone but their shadows are still there. Roads suddenly end in a green
	patch. Villages that were covered by clouds are overgrown by green woods and fields.		patch. Villages that were covered by clouds are overgrown by green woods and fields. Shadows
			of no longer existing clouds still darken the area.

	Selecting by color has the drawback that every area having a cloud-like color		Selecting by color has the drawback that every area having a cloud-like color

Bew at 22:07, 9 March 2007

2007-03-09T22:07:38Z

← Older revision		Revision as of 22:07, 9 March 2007
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	[[User:Bew\|Bew]] is working on a tool to automatically detect clouds. You call the tool with LANDSAT		[[User:Bew\|Bew]] is working on a tool to automatically detect clouds. You call the tool with LANDSAT
	images of band 1, 2, 3, 5, and 6. The tool creates a black and white image containing just		images of band 1, 2, 3, 5, and 6. The tool creates a black and white image containing just
	clouds as black fields. You can import this image as a layer and simply select all black fields.		the clouds as black fields. You can import this image as a layer and simply select all black fields.
	With this selection, ~~you can~~ call the 'Smart Remove'-tool after ~~changing~~ to the layer containing		With this selection, call the 'Smart Remove'-tool after having changed to the layer containing
	your pan-sharpened LANDSAT image. The tool is not ready for public use yet.		your pan-sharpened LANDSAT image. The tool is not ready for public use yet.


	[[Category:Scenery]]		[[Category:Scenery]]

Bew at 22:06, 9 March 2007

2007-03-09T22:06:05Z

← Older revision		Revision as of 22:06, 9 March 2007
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	Professional geographers use the LANDSAT infrared bands to distinguish between clouds		Professional geographers use the LANDSAT infrared bands to distinguish between clouds
	and white areas. This is called 'cloud detection using spectral features', which is		and white areas. This is called 'cloud detection using spectral features', which is
	~~scientific~~ for: if its white/greyish in the visible bands and darkish in infrared, it's a cloud.		short for: if its white/greyish in the visible bands and darkish in infrared, it's a cloud.
	With some refinement, clouds and snow can be separated. This might be useful for high mountain		With some refinement, clouds and snow can be separated. This might be useful for high mountain
	areas.		areas.

Bew at 22:04, 9 March 2007

2007-03-09T22:04:37Z

← Older revision		Revision as of 22:04, 9 March 2007
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	# Select the clouds by color		# Select the clouds by color
	# Grow the selection by a few pixels to eliminate pixels that belong to the cloud, but		# Grow the selection by a few pixels to eliminate pixels that belong to the cloud, but are too dark for 'select by color'
	are too dark for 'select by color'
	# Use the 'Script-Fu -> Enhance -> Smart Remove' tool		# Use the 'Script-Fu -> Enhance -> Smart Remove' tool

Bew at 22:03, 9 March 2007

2007-03-09T22:03:58Z

← Older revision		Revision as of 22:03, 9 March 2007
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	# Use the 'Script-Fu -> Enhance -> Smart Remove' tool		# Use the 'Script-Fu -> Enhance -> Smart Remove' tool

			Follow the links to see an example [http://beta.zooomr.com/photos/35232@Z01/762317 before]
			and [http://beta.zooomr.com/photos/35232@Z01/762318 after] 'Smart Remove'

			The clouds have gone but their shadows are still there. Roads suddenly end in a green
			patch. Villages that were covered by clouds are overgrown by green woods and fields.

			Selecting by color has the drawback that every area having a cloud-like color
			will be removed. Alternatively, you can select clouds by hand. The selection does not
			need to be accurate, but all details accidentally selected will vanish.

			Professional geographers use the LANDSAT infrared bands to distinguish between clouds
			and white areas. This is called 'cloud detection using spectral features', which is
			scientific for: if its white/greyish in the visible bands and darkish in infrared, it's a cloud.
			With some refinement, clouds and snow can be separated. This might be useful for high mountain
			areas.

			[[User:Bew\|Bew]] is working on a tool to automatically detect clouds. You call the tool with LANDSAT
			images of band 1, 2, 3, 5, and 6. The tool creates a black and white image containing just
			clouds as black fields. You can import this image as a layer and simply select all black fields.
			With this selection, you can call the 'Smart Remove'-tool after changing to the layer containing
			your pan-sharpened LANDSAT image. The tool is not ready for public use yet.

	~~See an example [http://beta.zooomr.com/photos/35232@Z01/762317 before] and~~
	~~[http://beta.zooomr.com/photos/35232@Z01/762318 after] 'Smart Remove'~~

	[[Category:Scenery]]		[[Category:Scenery]]

Bew at 21:41, 9 March 2007

2007-03-09T21:41:35Z

← Older revision		Revision as of 21:41, 9 March 2007
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	[http://www.logarithmic.net/pfh/resynthesizer Resynthesizer] is an amazing plug-in		[http://www.logarithmic.net/pfh/resynthesizer Resynthesizer] is an amazing plug-in
	for [http://gimp.org Gimp], which makes removing objects from pictures a lot easier.		for [http://gimp.org Gimp], which makes removing objects from pictures a lot easier.

			# Select the clouds by color
			# Grow the selection by a few pixels to eliminate pixels that belong to the cloud, but
			are too dark for 'select by color'
			# Use the 'Script-Fu -> Enhance -> Smart Remove' tool


			See an example [http://beta.zooomr.com/photos/35232@Z01/762317 before] and
			[http://beta.zooomr.com/photos/35232@Z01/762318 after] 'Smart Remove'

	[[Category:Scenery]]		[[Category:Scenery]]

Bew: New page: === Cloud Removal === Free satellite imagery often contains a lot of clouds. Removing them by hand with the Clone Tool of an image manipulation program is a tiresome task. Fortunately, t...

2007-03-09T21:31:18Z

New page: === Cloud Removal === Free satellite imagery often contains a lot of clouds. Removing them by hand with the Clone Tool of an image manipulation program is a tiresome task. Fortunately, t...

New page

=== Cloud Removal ===

Free satellite imagery often contains a lot of clouds. Removing them by hand with
the Clone Tool of an image manipulation program is a tiresome task.

Fortunately, there are better tools available.
[http://www.logarithmic.net/pfh/resynthesizer Resynthesizer] is an amazing plug-in
for [http://gimp.org Gimp], which makes removing objects from pictures a lot easier.

[[Category:Scenery]]