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GeoTif displays very dark

#1

Hi,

We are having trouble with some of our new GeoTiffs. They appear OK when viewed in ArcMap but are too dark in out ThinkGeo based application.

ImageComparison
ImageComparison1780×523 219 KB

I have attached a screenshot so you can see the difference. The darker one is from our ThinkGeo application and the lighter one comes from ArcMap. Is there a way to make it display lighter in ThinkGeo? I can send the original file if necessary, but it’s very large.

Thanks!

Steve

#2

Thanks Steven,
Yes. We do support add bright to the geotiff layer
geoTiffRasterLayer.GreenTranslation = 100;
geoTiffRasterLayer.RedTranslation = 100;
geoTiffRasterLayer.BlueTranslation = 100;

image
image2198×636 404 KB

Thanks

Frank

#3

Frank,

Thanks so much for the tip! What are the valid values of Red/Green/Blue translation? How do they all work together? Is it the higher the number the lighter the color or the other way around?

Thanks!

Steve

#4

Yes Steven,
Base on this document.
https://www.graphicsmill.com/docs/gm/brightness-and-contrast.htm

Bitmap brightness is the degree of pixel intensity. For brevity let’s assume that we are working with a grayscale bitmap. If most pixels of this bitmap have small values (e.g. close to 0), the bitmap is called dark . Vice versa, if most pixels have large values (e.g. close to the maximum value - 255 for 8-bit images, and 65355 for 16-bit images), the bitmap is called bright .

I tested the validate value should be 0 to 255. You can add 3 trackbars to your UI and bind the value with the Red/Green/Blue translation and play with different value until get the best result.

Thanks

Frank