2017-03-02, 02:17
Ringing Artifacts Explained
Days of Heaven 1080p Blu-ray
Wikipedia: In signal processing, particularly digital image processing, ringing artifacts are artifacts that appear as spurious signals near sharp transitions in an image. Visually, they appear as bands or "ghosts" near edges. The term "ringing" is because the output signal oscillates at a fading rate around a sharp transition in the input, similar to a bell after being struck.
Ringing can be introduced in various ways:
The common theory in image processing is to capture an image with the correct size and format for its intended purpose. If the image is too small, too large or too soft to be considered ideal for its end use, then unwanted manipulation of the image may occur in post-processing.
Pushing edge enhancement a little too far to compensate for a soft transfer or using sharp but simple upscalers such as Lanczos or Bicubic to upscale to HD resolutions almost always results in some visible halos being left behind. These sources are considered poor transfers and bad examples of video processing. This may not be bothersome to everyone, but ringing artifacts can make any video look noisy and distracting.
Definitions and Causes of Ringing Artifacts
Days of Heaven 1080p Blu-ray
Wikipedia: In signal processing, particularly digital image processing, ringing artifacts are artifacts that appear as spurious signals near sharp transitions in an image. Visually, they appear as bands or "ghosts" near edges. The term "ringing" is because the output signal oscillates at a fading rate around a sharp transition in the input, similar to a bell after being struck.
Ringing can be introduced in various ways:
- Image upscaling or downscaling is used during the mastering process;
- Edge enhancement is applied during the mastering process;
- The signal is bandwidth-limited, discarding too much information for high frequencies;
- The video renderer resizes with image upscaling or downscaling;
- The video renderer applies edge enhancement as a post-process.
The common theory in image processing is to capture an image with the correct size and format for its intended purpose. If the image is too small, too large or too soft to be considered ideal for its end use, then unwanted manipulation of the image may occur in post-processing.
Pushing edge enhancement a little too far to compensate for a soft transfer or using sharp but simple upscalers such as Lanczos or Bicubic to upscale to HD resolutions almost always results in some visible halos being left behind. These sources are considered poor transfers and bad examples of video processing. This may not be bothersome to everyone, but ringing artifacts can make any video look noisy and distracting.
Definitions and Causes of Ringing Artifacts
