GeoServer Raster Data Sources: satellite data's contrast issue

Question

I am trying to use my own satellite image as the basemap for a webapp, instead of OSM, Google etc imageries. In order to do that, I made a Raster Data Sources store inside my GeoServer, which is pointing towards a .tif file (having .prj and .tfw files along-with). I am on Ubuntu 14.04. Everything is working fine except the following issue.

As can be seen in the attached images, visualization of satellite image in QGIS is giving a good contrast and brightness. But importing the very same image inside GeoServer is producing low contrast/bright image, plus seams, which can be seen at the bottom section. Although I am using Tiling:Tiled in the GeoServer, it shouldn't create seams. Zoomin and out are also changing the contrast and brightness of the GeoServer image.

Can you explain the reason and remedy of this unexpected effect?

Answer 1

This looks like a 16 bits image.

Quick suggestion, the easiest thing to do is to preprocess this image and perform color correction upfront.

You can use QGIS itself or GDAL utilities (See this email: http://lists.osgeo.org/pipermail/gdal-dev/2012-March/032180.html)

Answer 2

As mentioned by @simogeo, since the orginal data was in 16bit data type, there were seams and performance issues.

The following command from terminal will convert 16 to 8 bit data type, provided the lower and upper values of 16bit data (which is 156 and 4095 in my case).

gdal_translate -of GTIFF -ot Byte -scale 156 4095 0 255 -co worldfile=yes image_16bit.tif image_8bit.tif