A device for converting signals from one standard to another. Converting between different color schemes with the same scanning structure is called transcoding. Converting between different scanning structures requires line and field interpolation, which usually introduces artifacts. Standards conversion between 525 scanning line and 625 scanning line signals is performed regularly. Conversion from DHEP to either NTSC or a receiver-compatible ATV system will require standards conversion. It may seem that it is more difficult to convert from 1125 scanning lines to 525 than from 1050 to 525, but in a pre-filtering converter, the difference, if any, may not be large. For dealing with the field-rate difference (HDEP 60 and NTSC 59.94), some DHEP to NTSC conversions are performed by slowing the HDEP recorders to 59.94-field playback. Others are performed through standards converters that periodically omit fields.