Image compression in signal-dependent noise.

The performance of an image compression scheme is affected by the presence of noise, and the achievable compression may be reduced significantly. We investigated the effects of specific signal-dependent-noise (SDN) sources, such as film-grain and speckle noise, on image compression, using JPEG (Joint Photographic Experts Group) standard image compression. For the improvement of compression ratios noisy images are preprocessed for noise suppression before compression is applied.

Immunity status in children with Bacille Calmette-Guerin adenitis. A prospective study in Tehran, Iran.

Objective: To determine the immunity status of children with Bacille Calmette-Guerin (BCG) lymphadenitis (patient group) and unaffected children (control group) in Iran.

Methods: We performed this longitudinal case-control study on 75 children between 2 months to 14 years old in Rasool Akram and Markaz Tebbi Hospital, Tehran, Iran during the period of 2 years (2000-2002).

Results: Ninety percent of patients had normal immunoglobulin, 10% had low level, 96.