Bandwidth Conservation Society /
Tutorial / Comparison Number 1
JPEG Source File / 25,874 Bytes
For comparison, we've included the source file in JPEG format. The image
was orginally designed and rendered with KPT Bryce as a Macintosh PICT file. It
was then opened and saved using GIF Converter. The JPEG options were set to No Compression and
Millions of Colors.
8-Bit GIF, System Palette / 12,594 Bytes
Here, the image was opened and saved using Adobe Photoshop (v2.5.1). The
original PICT was converted to Index Color, with the Sytem Palette and
Diffusion options selected.
Notice the heavy dithering in the sky and shadow areas. By forcing the image
into the available 256 Macintosh System colors, the heavy dithering encumbers
the quality.
8-Bit GIF, Adaptive Palette / 16,618 Bytes
This image was opened and saved using Adobe Photoshop (v2.5.1). The
original PICT was converted to Index Color using an Adaptive Palette, No
Diffusion. With the Palette changed to Adaptive, the image doesn't suffer from
the "Speckly" look of the System Palette image. The cost though is an
additional 4K in bytesize of the image.
Notice the flattening (posterization) of the colors in the shadow areas and
in the sky.
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