Bit depth required for colorspace

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Rumpelstielzchen
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Bit depth required for colorspace

Post by Rumpelstielzchen » 2014-04-10T11:02:49-07:00

Dear reader,

I've often read something like "use 16 bit depth with ProPhotoRGB to avoid color banding".

Well, my question was "how more worse than sRGB is ProPhotoRGB at 8 bit"?

here the short answer:
AdobeRGB1998.icc: max CIEΔE2000 1.644989 at <29.882812 29.882812 31.875000>, direction <0 1 0>
BetaRGB.icc: max CIEΔE2000 1.903843 at <29.882812 29.882812 31.875000>, direction <0 1 0>
ProPhotoRGB.icc: max CIEΔE2000 2.866776 at <17.929688 17.929688 19.921875>, direction <0 1 0>
sRGB.icc: max CIEΔE2000 1.168979 at <23.906250 23.906250 25.898438>, direction <0 1 0>

The values in <r g b> are of range 0..255

ProPhotoRGB's largest color granularity is about 2.5 times larger than sRGB, which would require 1.3 bit more Information than sRGB.

(I did not do a full exhaustive search, just 1/8 of all possible <r g b> values)

Here the C source ( cat ... | bzip2 -d -c | base64 -d ):

Code: Select all

QlpoOTFBWSZTWQv4w7EAAWpfgGAwe3/7Xz/n3n6/5//+UAX5poz3HdXd0IsarbaUwkimpiBqnmmU
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FUa3ixGuqtiIKphS8G/ZyMTo55OEnz8f4batW7q3lrF4S27q79vFxIxjaqyoxlEwT8uuFy5Y5yiv
P0aieD5vP1TpMHM2ZZVeJSTI+9Znmq4CZei8piYYzRomeWMXeAUVGK7raJZAgZkJOTtYDsW6sdOl
FYBSs01vEHSsvL7OKFa1SqkJHXRpYjahJ6OpZFkCdMrvOEOfmmpkpHS+htx76jm+efaOwPaqK55Y
B51rYQ7Ha6WX7RB2lCApk6D4aBouQEhsnXqJgkmFraBi5O/DPBA68eQEln05609wnec5TBglcBIY
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2SHavz4hOqNNTG6zJLJc1qd3mNnQjcUeYkwzVIsGg9J1lpJlVyBjLftAs17HAaUYsMFesgwcCicR
HbkV3cb0pZEdFxqVoVE4QGHGR30p6yjFCv3TYioTZZuskmzpkuE9T0aHsH6iij/xdyRThQkAv4w7
EA==

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