View Full Version : Salt-and-pepper noise on DFK23GM021

January 16, 2014, 15:14:42
I'm using three DFKGM021 cameras for a multicamera device. For my application I need to segment colours on the images, so I change the RGB channels to HSV via software.
I've noticed a strong "salt-and-pepper" noise in the H channel after the conversion and it seems to me that it's present also in the RGB images. As you can see, the three images attached are three different shots taken with a single camera with a 1s interval and it's clear that the wall on the background (which is on focus) is not white but mde up by red, blue and green pixels changing, by the way, from image to image. This makes the segmentation of the colors in the image quite impossible.
Is there something I can do to avoid such noise?

The images were taken with the ICCapture software, leaving the auto properties enabled (only an external trigger was used). The problem is not solved if the gain is reduced to zero.

Thank you very much,


Stefan Geissler
January 16, 2014, 15:31:17

I suppose, this is usual noise you see. The M021 sensor is a little bit hard to handle.

Therefore, you may try the Denoise filter in IC Capture. If using the Denoise filter (you may need to update IC Capture, if an error occurs, from http://www.theimagingsource.com/en_US/support/downloads/), you need more than one image, so the filter can build an average image.

January 16, 2014, 15:47:26
Do I have to expect this noise level from my cameras or there is any hardware setting that I can try to reduce it (white balance, gain, exposure)?
I've tried to use the denoise function but the result is still noisy...

Stefan Geissler
January 16, 2014, 16:03:59
Which value do you use in the denoise window?

However, if this is too much noise, you should consider using a CCD instead of a CMOS camera.