Image Rejection
Image rejection describes how well a tuner suppresses an unwanted signal at an image frequency of its reception system.
An image can be converted into the same intermediate-frequency path as the wanted signal. Rejection is expressed in decibels under specified conditions.
Image Rejection — Tuner
For a tuner, the rating describes suppression of this particular interference mechanism. Greater rejection under comparable conditions means less response to the unwanted image-frequency signal.
Compare the same reception band, test frequency and measurement conditions. Image rejection is not a general score for every kind of interference and should not be substituted for adjacent-channel selectivity or capture ratio. It also does not describe audio stereo separation or rejection of noise already present in the wanted broadcast.