Broadcast reference monitors must be used for video compliance at television or television studio facilities, because they do not perform any video enhancements and try to produce as accurate an image as possible.[1][2][3] For quality control purposes, it is necessary for a broadcast reference monitor to produce (reasonably) consistent images from facility to facility, to reveal any flaws in the material, and also not to introduce any image artifacts (such as aliasing) that is not in the source material. Broadcast monitors will try to avoid post processing such as a video scaler, line doubling and any image enhancements such as dynamic contrast. However, display technologies with fixed pixel structures (e.g. LCD, plasma) must perform image scaling when displaying SD signals as the signal contains non-square pixels while the display has square pixels.[4] LCDs and plasmas are also inherently progressive displays and may need to perform deinterlacing on interlaced video signals.