Logical screen descriptor of GIF file. Contains very basic information about Gif.
sorted:Bool
Specification: Indicates whether the Global Color Table is sorted.
If the flag is set, the Global Color Table is sorted, in order of
decreasing importance. Typically, the order would be decreasing
frequency, with most frequent color first. This assists a decoder,
with fewer available colors, in choosing the best subset of colors;
the decoder may use an initial segment of the table to render the
graphic.
pixelAspectRatio:Float
Factor used to compute an approximation of the aspect ratio of the pixel in the original image.
colorResolution:Int
Specification: Number of bits per primary color available
to the original image, minus 1. This value represents the size of
the entire palette from which the colors in the graphic were
selected, not the number of colors actually used in the graphic.
For example, if the value in this field is 3, then the palette of
the original image had 4 bits per primary color available to create
the image. This value should be set to indicate the richness of
the original palette, even if not every color from the whole
palette is available on the source machine.