Image Noise and Compression

18 January 2007

My PowerShot S2 produces very noisy images at ISO 400, and I started wondering if maybe the camera could smooth some of this out for me during JPEG compression. I usually have the camera set to super-fine quality to minimize the compression, so I cut it down to normal compression (which also cuts the image size to 1/5th the size of the super-fine image). The noise was still there.

In fact, I almost couldn't really tell a difference in the image quality of my super-fine test picture and the normal picture. I had to go take some more test pictures in better light and really blow up the pictures to notice the slightest change in image sharpness.

Ultimately, I'm still opting to shoot the images at super-fine, since I have plenty of SD cards (2G). Letting Gimp compress them down in post-processing seems to get the pictures to be almost the same size, but preserves more detail. The slightly higher quality seems to also keep the detail through the noise reduction method I use.

Filed Under: Photography