Eliminate noise

Denoise of Nokia 808 PureView high ISO pictures.

High ISO pictures are noisy.
Pictures taken with the Nokia 808 PureView at high ISO values are noisy. With pictures taken “on the go” we have to accept this or make the best of it with the denoise feature of an image editor or with a dedicated denoise app. These features and apps do a good job but the trade off is always a considerable reduction of sharpness and details. But suppose you have a static scene then for high ISO pictures there is a method to get clean pictures in which noise is strongly reduced. The trick is to put your 808 on a tripod and make a serie of, let say, 10 pictures. The interval feature of the standard camera app of the 808 is very useful for this. Set to 10 images and an interval of 5 sec you are done within 1 minute.

Noise is random; pixels are not.
Why the heck are we taking 10 pictures when we only want to have one? The answer is that in all pictures the pixels of the scene are on exact the same place (808 on a tripod) but the noise is distributed randomly. And by combining those 10 pictures to one the algorithm of the combining software can filter out the randomly distributed data.

Examples
The following picture shows a 100 % detail view of a single shot at 1600 ISO. The 808 was set to full resolution (38 MP). Many details are lost due to heavy noise.

1x1600-ISO-38MP-100%

The next picture shows the same 100 % detail view of a combination of 10 shots at 1600 ISO. These 10 shots were processed in Photoshop. As we can see now more details are visible and the picture is clean because the processing filtered out the noise.

10x1600-ISO-38MP-OPE-100%

We get about the same or slightly better result with these 10 shots when we use the denoise feature of Oloneo PhotoEngine. See next picture.

10x1600-ISO-38MP-Median-100%

Details of the processing.
Open all 10 shots in Photoshop (you need the extended editon) and stack them all above each other in layers. Then convert these 10 layers to one smart object (via the layer menu). Once converted to a smart object you choose stack mode (again via the layer menu) and set it to median. Then you are done.
In Oloneo PhotoEngine you add the 10 shots to the so called Project Image Selection and choose Create DeNoise Project. All 10 images need to have the same aperture and exposure values. The processing in Oloneo PhotoEngine is much faster and straight forward compared to the PhotoShop method. Moreover the result is slightly better. You can download a 30 days trial of PhotoEngine HERE.


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