dehazing photographs

How to Remove UV Haze from Photographs

This is probably the worst possible problem many photographers face when taking that awesome landscape shot of that picturesque train chugging up a distant mountain. Once you get back home and check your final image you nothing but disappointed to see so much blue-haze in the mountainous foreground. Infact your probably wanting to delete it as its that bad - but hold one a second; there is a way you can fix it and completely remove that ugly blue-haze!

GIMP and Paint.NET to the rescue

These are 2 free programs which can be downloaded off the net which provide some excellent photo editing facilities. Once you have installed both applications, you can go ahead and use the GIMP to open your hazy image for editing.

The easiest way to achieve this is to use the following from the menu.

Colors -> Auto -> (White balance)

However this will only remove a certain percentage of the haze and give good results. However if your after better results, you will need a bit more manual labor. The following example shows a hazy image which is opened in GIMP and ready to be enhanced.

By using the Menu Color -> Levels, you can re-adjust the Input values of the image thus removing the undesired colors...

Move the Left Input Slider until the you have covered the very end of the flat line. This will remove additional white light that's present in pictures. Now switch the Channel: value to BLUE, and move the Left Input Slider once again to the point where the flat line ends. Once you have done this, you will notice an instance change in the quality of the Photo. If the quality is still not desirable, you can continue and add a Mask (From the menu: Filter -> Enhance -> Unsharpen Mask..)

Set the below mentioned values for optimum results and click OK (this process might take a few seconds)

Once you have completed this step, you will notice a significant reduction in the UV haze as follows... You can also use the Paint.NET to reduce Hazy Photos by using the menu: Adjustment -> Levels and reducing the Input Level as mentioned above. Once you have fixed that problem, use the menu: Effects -> Photo -> Sharpen+ tool which is actually the Unsharpen Mask tool.

By experimenting with the Values and Amounts, you can de-haze the Photo's to a certain degree...