Epson PSB.2003.04.004 User Manual
Page 8
PSB No: P-0078
Page: 3 of 3
Midtones:
Pixel:
The values in a continuous tone or halftone image correspond to
the medium values in the range. Generally the values is between
30% to 70%.
A relative unit of measuring resolution. Pixel size is relative, due
to the output device. For example, a monitor pixel may be
different in size compared to a scanner pixel. Pixels can be
measured absolutely when fixed to another standard, like pixels
per inch.
Posterize:
To limit the number of shades in an image to create a highly
contrasted effect.
Screen Angle:
The angle at which halftone dots are lined up. As mentioned
earlier, newspapers commonly use a screen angle of forty five
degrees.
Smoothing:
An operation that softens the edges between adjacent tones.
Spot Function:
A procedural body in the Postscript language that defines the
shape of the halftone spot.
Subtractive
Colors that are produced by mixing inks or paints. The three
Primary Colors:
subtractive colors are cyan, magenta, and yellow. This process
reduces the amount of light that the human eye receives. The
absence of color is white (0%), while full intensity is black (100%).
This model is used in printing.
Threshold:
The selected gray level above which gray shades are converted
to white and below which gray shades are converted to black.
This is used to produce higher contrast or posterize images.