A text enhancement unit is introduced in order to alleviate the
degradation of text characters on computer or television displays. The
text enhancement unit uses an enhancement process to regain uniformity
and intensity that may be lost during image processing. The text enhancer
unit may be placed between an image processing unit such as a scaler,
de-interlacer, or DSP, and a computer or television display to improve
the quality of text characters that may have become degraded by image
processing performed by the image processing unit. In one embodiment, the
text enhancer unit improves contrast by multiplying pixel intensity by an
intensity multiplier. In a second embodiment, the text enhancer unit
improves contrast using a threshold operation which outputs either a very
high or very low intensity pixel. In an third embodiment, the text
enhancer unit improves contrast using a threshold operation which outputs
either a very low intensity pixel or a pixel multiplied by an intensity
multiplier. In a fourth embodiment, the text enhancer unit improves
contrast using a threshold operation which outputs either an unchanged
pixel or a pixel multiplied by an intensity multiplier. In a fifth
embodiment, the text enhancer unit improves contrast using a dual
threshold operation which outputs either a very low intensity pixel, a
very high intensity pixel, or an unchanged pixel.