Digital Image Formats - A Practical Guide to Video and Audio Compression - page 128

Aliased

Antialiased

Vector

Figure 6-7 Anti-aliasing effects.

The industry is settling on some standard screen sizes for D-cinema that coincide
with the HDTV specifications, so imaging areas of 1920 × 1080 will become popular.

6.9.5 Resolvable Detail

You would think that a cinema screen would require more than 1080 lines to provide an
image of sufficient quality. Reducing the pixel resolution to 1080 lines is feasible, though,
because the audience only resolves about 900 lines at the normal viewing distance—even
in a good theater. IMAX theaters are a special case because the viewer sits a lot closer to
the screen than normal. Using the best equipment, such theaters achieve approximately
2000 lines of resolution on a 35mm print. Since the detail is just not visible, it is pointless
to put the extra information in the output image. While the justification is there for 35mm
to be printed at that quality, the potential savings in storage capacity and bit rate for
D-cinema are more compelling.
Figure 6-8 shows how the resolving capabilities of the human eye limit the useful-
ness of higher-resolution displays.

Line 100

1080 line
image projection

Line 101

Figure 6-8 D-cinema resolving power.