Photoshop Editing Hints: How to Use Color Noise Reduction

One of the advantages to shooting digital photographs is that you're almost always guaranteed a good picture. As long as you have a copy of Photoshop available, then you're generally just a few steps away from another great shot.

One of the biggest reasons that people will hit the "delete" button on their digital camera when previewing a picture is because it appears too dark, however by knowing a few tricks you can easily overcome some of the most extreme lighting situations and salvage that picture that was headed straight for the trash can.

To start, you'll need an image which has extremely poor lighting situations. In my example photos you can see that the first shot is almost so dark that you can't even tell there's an image there at all. Trust me, there is, and in just a few seconds I'll show you how to get to yours as well.

With your darkened photo open, you'll want to first adjust the levels in the photograph to force the image to appear in the photo. You can find the levels adjustment by going to Image, Adjustment, Levels in the Photoshop menu.

With the levels menu open, you'll want to adjust your high and low range to where the peaks appear in your histogram. Already you should be able to tell that the photo is starting to emerge. Now, using the mid range indicator, slide to the left until you've lightened the image up just enough to be able to see what's going on without losing all definition in the image.

Already we've uncovered a buried treasure that was once hidden behind a dark image, however with the extreme adjustments we've uncovered a lot of extra "noise" that was created in the process of bringing out the color in the image. Not to worry, by using a handy filter which allows us to reduce color noise we'll be able to clean that up in no time.

On your menu go to Filter, Noise, Reduce Noise. This will cause a box to appear on your screen which will show you the noise filter adjustments, as well as provide a preview of your altered image.

The first option you have in the reduce noise box is to set the strength of the filter. This level is adjustable from a setting of 1 to 10. Test it at each setting to see which effect is going to work the best for the level of noise you have in your photo, in the case of my horribly dark photo, I needed to set it all the way to 10.

The next option you have is the percentage of which to preserve the details in the image. Anytime there is a lot of noise that needs to be corrected, there's the chance that it can destroy some of the finer details in the image. While it's generally impossible to do noise reduction without losing some detail image don't worry too much, because we'll be able to get some of that detail back in a later step. In my example image, I lowered my preserve details setting all the way to zero to get as much noise reduction as possible.

The next option in the noise reduction box is the percentage of noise you want to reduce. Again, my image being the extreme case, I went for the full 100%. Your image, however, might not be quite so bad so play with this amount and watch your preview window to see how the effect is working for you.

The last option in the noise reduction box allows you to resharpen the details in the image that might have been lost through noise reduction. Generally I leave this setting at zero, since I find that you have better sharpening control by going to the Filters, Sharpen, Unsharp mask filter.

There is also a check box which can allow you to remove the JPEG Artifacts from the image. Digital cameras often capture images in JPEG mode which can cause for noise to occur due to the compression of the image. Checking this box can reduce the effect of to much compression in your image. Try checking and unchecking this box to see what kind of affect it has on your image preview.

Advanced features in the noise reduction box allow you to control noise reduction on channel for channel basis, reducing noise individually on each of the Red, Green and Blue layers. If you aren't satisfied with the results you're getting through the basic controls, then try using the advanced mode to see if that has a better affect on your image.

Once you're satisfied with your noise reduction options, select okay from the noise reduction menu and your changes will be applied to your image. To resharpen your image, next go to Filters, Sharpen, Unsharp Mask in order to bring back some of the detail lost in the noise reduction process.

With just a few adjustments and a few extra minutes, even a picture doomed for the garbage can be salvageable if you know the right steps to take. So next time you find yourself out shooting pictures with your digital camera, don't be so ready to hit the delete button - there might just be a good picture there after all!