MSIE & Netscape Color Palettes
Robb
but may not correctly understand: (please feel free to correct any incorrect
info below)
1-bit graphics card has 2 color palette (black & white)
(2 bits to the power of 1 or 2 x 1 = 2 colors)
4-bit graphics card has 16 color palette (standard VGA)
(2 bits to the power of 4 or 2 x 2 x 2 x 2 = 16 colors)
8-bit graphics card has 256 color palette (vga?)
(2 bits to the power of 8 or 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 = 256 colors)
16-bit graphics card has 65,536 (64,000) color palette
(2 bits to the power of 16 or 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2
x 2 x 2 x 2 x 2 = 65,536 colors)
32-bit graphics card has 16,777,216 color palette
(2 bits to the power of 32 or 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2
x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2
x 2 = 16,777,216 colors)
Palettes are essentially look-up tables, stored on ? from which color data
to be displayed is retrieved from and displayed on monitor screen by video
card (?).
Windows OS was constructed with 8-bit video card technology in mind and
utilizes 8-bit video card 256 color palette.
Browser software, Netscape and MS Internet Explorer, were constructed with
8-bit video cards as model.
(Question 1: Does Windows operating system and/or browser software retrieve
colors to be displayed from their own color tables or from standardized
color palette of 8-bit video card or does Windows and/or browser software
"supplant" the video card palette with their own? Or is there other info I
am missing, ect.?)
Windows OS "reserves" 20 colors from 256 color palette for own use.
Netscape "reserves" 13 of remaining 236 colors (256 - 20 = 236) for own use
(Netscape logo). I am assuming colors reserved by Netscape are reserved from
video card palette (table). This leaves 223 colors from original 256 color
palette (256 - 20 - 13 = 223).
(Question 2: I read some article that referred to colors stored in palette
are like slots. The article inferred (at least to me) that if a certain
color was being displayed then that color was no longer available for other
applications to use and if requested then the "duplicated" color selection
would be substituted or "dithered".)
MS Internet Explorer: I have not discovered if certain colors are "reserved"
and what these colors are and if colors reserved, whether colors are being
reserved from video card palette (table) or from MSIE's palette.
Netscape developed 216 "color-safe" palette from remaining 223 colors. When
these colors specified, browser software would recognize color within it's
own internal palette and specified color would be selected and displayed
properly (neither substituted nor "dithered).
(Question 3: referring back to second question; Once color within
"color-safe" palette selected and displayed is this same color still
available or if selected again would this "color-safe" color be substituted
or "dithered"?)
MSIE developed its own "color-safe" palette of 216 colors, differing only
from the initial color used in the palette's construction (MSIE rotates a
constant "red" and Netscape rotates a constant "blue"). The 216 color-safe
colors within both MSIE and Netscape are identical.
(Question 4: I read article that said MSIE displays "differently" some
colors in 216 palette, which to me means that these palettes (MSIE's and
Netscape's) are different. Are there differences other than the method of
construction? If differences exist, I would appreciate any info and
details.)
Restatement: Netscape and MSIE were developed with 256 video palette as
model. Netscape reserves 13 colors, Windows operating system reserves 20
colors, leaving 223 colors left from original 256 colors of video card
palette. Netscape developes palette (table) of 216 "color-safe" colors from
remaining 223 colors. MSIE developes same "color-safe" palette of 216
colors. Any color from "color-safe" palette will not be substituted or
dithered.
Question 5: Are video card palettes standardized by whatever "bit"
technology of card or do different video cards of the same "bit" have
different palettes? If the latter is true, then netscape and MSIE either use
palette colors of their own and somehow remap the video card palette with
their own palette or the same specified color will display differently
within Netscape or Internet Explorer.