Permanently change image brightness

[BarbaraBrilmayer_Bakti]

Hi all,

is there any possibility to make permanent changes to the brightness of an image (img file), i. e. to alter the file pixel values? I have 2 tiles of a satellite image and I would like to adjust the brightness of one tile to the other. When displaying both images in ArcMap, they perfectly fit together when I increase the brightness of one tile about 2%. However, changes only affect the display of the image, no changes are made to the file pixel values of the image. But I would like to make these changes permanent. I am working with a 4 band (R, G, B, IR) satellite image which underwent atmospheric corrections (with ATCOR) and ArcGIS Desktop 10.1. I also tried histogram matching for the 2 tiles with another program which did not yield the desired results - the display brightness adaption would be perfect for matching the 2 tiles.

I would really appreciate any hints/ suggestions.

Cheers
Barbara

[CarrieDavis]

Hi Barbara,

If you are interested in adjusting one of the images you may want to try adjusting the brightness using the Image Analysis window.
If you want to permanently change the brightness, highlight the raster of interest listed in the Image Analysis window, adjust the brightness, then under the Processing tab click the Save icon. 

Using the Image Analysis window.
http://resources.arcgis.com/en/help/main/10.1/index.html#//009t000001tm000000

Also, another option is to use a mosaic data set to color match/mosaic satellite imagery for display purposes and still keep the original values.

Color Balance Mosaic Dataset
http://resources.arcgis.com/en/help/main/10.1/index.html#//0017000000sw000000

Color correcting a mosaic dataset
http://resources.arcgis.com/en/help/main/10.1/index.html#//009t00000041000000

If needed, you can always then export/copy an area or the whole mosaiced raster from the mosaic dataset.
Hope this gives you somewhere to start.