Artifacts (Click the images to see enlarged versions):
Display Setting Error
The graphic card colour resolution setting on this colour monitor is set too low. The monitor cannot display continuous grayscale.
Graphic Card Fault
Possible reasons for this fault: Software defect, or hardware defect on the graphics card, or memory defect in the video monitor. System was replaced.
Refresh Failure
When a window of another program is opened and closed, the video card must refresh the display with the previous background. This was intermittantly failing on this system, leaving black patches.
Beat Frequencies
When dealing with digital images, one has to be aware of the introduction of spurious artifacts by the interaction of frequencies. Click on the image to see more...
16 bit Graphics
Improper display settings can result in artifacts. The known artifact in this image (calibration failure on the Thoravision) is made worse when the image is reprocessed and displayed on a monitor with 16 bit color setting.
LUT Error
Corruption of Look Up Tables leads to inconsistent display of grayscale bands on monitor.*
Burn-In (CRT)
CRT displays work when a phosphor is made to glow after being scanned by an electron beam. This phosphor can be permanently damaged if a static image is left on the screen for long periods of time, leading to use of screen savers to prevent burn-in.
Persistence (LCD)
The crystals that electronically conform to make the image can develop a memory and retain a latent image of images left on the screen for long-periods of time. Persistence can be corrected with screen-savers.*

*Medical Class video monitors employ Look Up Tables (LUTs) to help adjust the image quality from an external source to match the characteristics of the video system. This helps ensure the image looks like it did at the source. When the Look Up Table is defective, or programmed incorrectly, certain information in the image is not displayed properly. The left and right bands highlighted by yellow should be uniform, but are not because of LUT distortion. On an image, this would appear as black and white specks, possibly mimicking anatomy.