In some cameras, noise reduction can be activated or switches on automatically at slow shutter speeds. Note that noise reduction often requires more time for the photo to be written to the memory card, during which you will be unable to take a picture.
This is the grainy look you find in a digital image caused by image artifacts. It may also appear as flecks of color that should not be there. It is usually noticeable in shadow areas, and generally produced when shooting in low light. It is caused by high ISO required for low light shooting. Noise is almost always unwanted and unattractive.
Random errors and fluctuations in an image. Noise can be distracting across a sequence of frames.
â€“ A mottled or grainy appearance in images caused by electrical fluctuations on the image sensor. Noise becomes more pronounced as the camera s ISO (light sensitivity) is raised, causing decreased detail and distorted colors. Noise is not always visible in small versions of photos used for online posting but can become obvious in large prints or cropped photos.
A common bugaboo of digital photography, noise is the appearance of color artifacts in a digital image. Mostly noticeable in the shadow areas of images captured at higher ISO ratings, the image processors used in many current digital cameras utilize noise-suppression software to minimize the appearance of noise artifacts. Heat build-up due to continuous shooting in hot environments can also cause noise artifacts within digital images. Noise is considered the digital version of grain in film negatives.
Misinterpreted pixels found in your digital image, usually occurring in longer exposures. Can be seen as misplaced or random bright pixels in the picture
Part of a measured signal which is different from the original signal. In an image, noise is especially visible in uniform areas
Random coloured pixels that appear in dark or shadow areas when the light levels are below the camera s CCD sensitivity range. Noise is also often seen from scans made using a scanner that doesn t have a wide enough dynamic range to cope with the shadow and highlight areas in one scan. Some image editing programs have a Noise filter that adds a grain pattern to the image to make it look more like a natural photograph taken using film.
Word derived from audible hiss heard when listening to weak radio transmission, is unwanted signal such as TV snow and speckling or grain in digital images. Tends to be most noticeable in plain, solid areas.
A type of image artifact (mottling or graininess) visible in photographs taken at high ISO sensitivities or slow shutter speeds.
The Degradation of image quality and Definition as a result of such problems as low light levels and what David Eisendrath liked to call gremlins.
A process in a digital camera s image processor in which the artifacts caused by pushed ISO ratings or other electrical or heat-related artifacts are suppressed or eliminated in an image.
For a multichannel image, matrix giving the covariance of the noise in the different channels.
â€“ An operation in the image processor that improves a noisy image by targeting and eliminating stray unwanted pixels (usually colored dots that are very different from the dots surrounding them). Noise reduction also removes some detail, however.
Algorithm aiming to retrieve the part of the signal directly related to the scene