Frame rate control

Frame rate control (FRC) or temporal dithering is a method for achieving greater <a href="/facts/Color_depth/0X7zI9BP">color depth</a> particularly in <a href="/facts/Liquid-crystal_display/8B6xGBEz">liquid-crystal displays</a>.
Older, cheaper, or faster <a href="/facts/Liquid_crystal_display/8B6xGBEz">LCDs</a>, especially those using <a href="/facts/Twisted_nematic_field_effect/vIgktRAy">TN</a>, often represent colors using only 6 <a href="/facts/Bit/S972NSaD">bits</a> per RGB color, or 18 bit in total, and are unable to display the 16.78 million color shades (24-bit <a href="/facts/24-bit_color/0X7zI9BP">truecolor</a>) that contemporary signal sources like <a href="/facts/Graphics_card/bcKfPyFt">graphics cards</a>, <a href="/facts/Video_game_console/K72D1NSS">video game consoles</a>, <a href="/facts/Set-top_box/hAsUsw67">set-top boxes</a>, and <a href="/facts/Video_camera/pu84VbC7">video cameras</a> can output. Instead, they use a temporal <a href="/facts/Dither/fCBytTzz">dithering</a> method that combines successive colors in the same pixel to simulate the desired shade. This is distinct from, though can be combined with, <a href="/facts/Dithering/fCBytTzz">spatial dithering</a>, which uses nearby pixels at the same time.
FRC cycles between different color shades within each <a href="/facts/Refresh_rate/7mGJs7Dz">new frame</a> to simulate an intermediate shade. This can create a potentially noticeable 30 Hz (half frame rate) flicker. Temporal dithering tends to be most noticeable in darker tones, while spatial dithering appears to make the individual pixels of the LCD visible. TFT panels available in 2020 often use FRC to display <a href="/facts/Color_depth/0X7zI9BP">30-bit deep color</a> or <a href="/facts/HDR10/VP97NWpz">HDR10</a> with 24-bit color panels. Temporal dithering is also implemented in software, for if the display itself does not, as for instance <a href="/facts/Graphics_processing_unit/PTK1RQVp">GPU</a> <a href="/facts/Device_driver/rDYnHU1G">drivers</a> from both <a href="/facts/AMD/CB1G7QTb">AMD</a> and <a href="/facts/Nvidia/8QfCgqbu">Nvidia</a> provide the option, enabled by default on some <a href="/facts/Computing_platform/DmKwp5Bk">platforms</a>.
This method is similar in principle to <a href="/facts/Field-sequential_color_system/v521Hhw1">field-sequential color system</a> by CBS and other sequential methods, such as used for grays in <a href="/facts/Digital_Light_Processing/jxMs8emm">DLP</a>, and also colors in single-chip DLP.
In the demonstration video green and cyan-green are mixed both statically (for reference) and by rapidly alternating. A display with a <a href="/facts/Refresh_rate/7mGJs7Dz">refresh rate</a> of at least 60hz is recommended for this video. Pausing the video shows that the perceived color of the bottom-right square during playback is different from the color seen in any individual <a href="/facts/Film_frame/27Uqo8WN">frame</a>. In an LCD display that uses FRC the colors that are alternated between would be more similar than those in the demonstration video, further reducing the flicker effect.

Frame rate control open-in-new

Frame rate control