Képzaj

Képzaj is a Hungarian term that translates to "image noise" or "picture noise." It refers to random variations in brightness or color information in digital images. These variations are not part of the actual scene being photographed but are introduced by the image acquisition process or subsequent manipulation.

Képzaj can manifest in several ways, including random speckles, color blotches, or grainy textures. It can degrade the visual quality of an image, making details appear indistinct and colors less vibrant. The causes of képzaj are diverse. In digital cameras, it can arise from the electronic sensors themselves, particularly when capturing images in low-light conditions or at high ISO sensitivities. Heat generated by the sensor during exposure can also contribute to noise.

Furthermore, image compression algorithms, especially lossy ones like JPEG, can introduce artifacts that are perceived as noise. Editing processes, such as adjusting brightness and contrast, can sometimes amplify existing noise or introduce new noise if not performed carefully.

Different types of képzaj exist, including luminance noise (affecting brightness) and chrominance noise (affecting color). The appearance of noise can vary depending on the camera, settings, and image processing. While often undesirable, in some artistic contexts, a certain level of grain or noise might be intentionally applied to achieve a specific aesthetic effect. Techniques for reducing képzaj, such as noise reduction filters in image editing software or in-camera processing, are commonly employed to improve image clarity.