image sharpening

[techwriter]

Hi,

What techniques do you use to sharpen images in preparation for photoscenery?

I have been working with some 1-meter GeoTIFF imagery of the Mojave desert and resampling it with the FSX SDK, but the imagery just doesn't look as good from the air unless I first apply a high-pass filter to sharpen it. The only way I can currently do this is to create a bitmap (BMP) of the imagery and sharpen it in Paint Shop Pro, save it, then resample the BMP using less-than-optimal geolocation.

I'd prefer to work with GeoTIFF format because of more accurate geolocation, but Paint Shop Pro won't import a GeoTIFF (so I can sharpen it) and save it back out as a GeoTIFF.

Just curious if anyone else does any image sharpening and what tools you use.

Thanks!

 

[HolgerSandmann]

Hi there,

there are two pretty easy options to allow for editing of geotiff images:

1. re-insert the original geotiff tags into the edited .tif file using the free GeoTiffExaminer http://www.mentorsoftwareinc.com/FREEBIE/FREE0699.HTM

2. transfer the original georeferencing information into the .inf file and therefore not worry about the original geotiff encoding anymore; see http://www.fsdeveloper.com/forum/showthread.php?t=8415

Whether sharpening or other image processing methods improve a source file or not very much depends on the source itself. I find that I need to do fairly intensive image editing in order to match raw orthoimagery to the hue and brightness values of the surrounding ground textures.

Cheers, Holger

 

[Timmo]

This is more a personal preference, but I find turning the 'Ground Detail' tickbox off in the display settings makes aerial imagery look better (I think that is what it is termed: It puts a repeated detail texture across the ground textures to try and make it look more detailed than it is)

 

[=Hollywood=]

I have to agree with Timmo there, also eats up some compute cycles.

Holger, thanks for that link to geotiff examiner, that's exactly what I need to make water mapping easier. Does it per chance do batch processing?

 

[techwriter]

Thanks for the great suggestions all! I'll do some more experimenting and try the GeoTIFF examiner too. In the mean time, what programs do you all use to do color correction and image enhancement with large mosaics? I have 2.75 GB of RAM on my computer, but Paint Shop Pro still chokes on large images, and it takes forever to do anything!

 

[=Hollywood=]

I use Adobe Photoshop CS2, CS3 has some extra features too but the program costs about $600 new. About $200ish for the upgrade from a previous version of Photoshop...