Policy
Turn off smart image dithering
This policy setting specifies whether you want Internet Explorer to smooth images so that they appear less jagged when displayed. If you enable this policy setting, smart image dithering is turned off. The user cannot turn it on. If you disable this policy setting, smart image dithering is turned on. The user cannot turn it off. If you do not configure this policy setting, the user can turn on or turn off smart image dithering.
28a67d475295 SmartImageDithering Registry
Copy registry mappings
HKCU\SOFTWARE\Policies\Microsoft\Internet Explorer\SmartDithering (enabled) = 0
HKCU\SOFTWARE\Policies\Microsoft\Internet Explorer\SmartDithering (disabled) = 1 Policy notes
This policy setting specifies whether you want Internet Explorer to smooth images so that they appear less jagged when displayed. If you enable this policy setting, smart image dithering is turned off. The user cannot turn it on. If you disable this policy setting, smart image dithering is turned on. The user cannot turn it off. If you do not configure this policy setting, the user can turn on or turn off smart image dithering.