0
\$\begingroup\$

If human eyes are more sensitive to red, green more than blue, also more sensitive to brightness than color. If there are 24 bits per pixel, are the images modified behind the scenes for human vision? How can we improve image for humans based on this? Or it is not really required? How could we make best of these 24 bits?

\$\endgroup\$
6
  • \$\begingroup\$ Check here to get idea how images are generated in camera (the sensor part): en.wikipedia.org/wiki/Bayer_filter \$\endgroup\$ Commented Sep 17, 2021 at 8:53
  • 1
    \$\begingroup\$ @RomeoNinov ok checking \$\endgroup\$ Commented Sep 17, 2021 at 8:55
  • \$\begingroup\$ Also one more point: the information from sensor (RAW file) is 12,14,16 bits per colour which make total value of 36, 42 or 48 bits en.wikipedia.org/wiki/Raw_image_format \$\endgroup\$ Commented Sep 17, 2021 at 9:00
  • \$\begingroup\$ @RomeoNinov ok. I went through the wikipedia pages, I am still not able to understand how we capture/improve images for humans. Like I understood there are twice as many as green sensors than blue, red and they are used for luminance. But, not able to understand how is that related to improving images for humans (since eyes are sensitive towards red, green than blue, and also eyes are more sensitive towards brightness than colors) \$\endgroup\$ Commented Sep 17, 2021 at 9:09
  • 1
    \$\begingroup\$ You might expand on what you mean by "improve" Historically, chemical prints increased contrast and hence saturation in the midrange while rolling off the more luminous regions. People find this more pleasing than a colorimetric (accurate) print. In other words, "accurate" isn't the same as "improve" for most situations. Exceptions are in scientific imaging and a few others. \$\endgroup\$
    – doug
    Commented Sep 17, 2021 at 15:19

1 Answer 1

2
\$\begingroup\$

The gold ring of fine arts (predates photography), graphic arts, and photography is to make a faithful image. Fine art suffers because canvas, paper, dyes, and pigments have limitations. Early on, black & white photography suffered, colored objects were rendered incorrectly (wrong shade of gray). Green foliage too dark, rosy cheeks and lips almost black. This happened because early films only recorded violet and blue. Hermann Vogel, Professor of Photography Berlin Technical in 1867 discovered how to make film record blue and green (orthochromatic film). His graduate student in 1884 found the secret, films gained red, green, and blue sensitivity.

The world viewed the first color picture in 1855 when James Clark Maxwell projected and superimposed three black and white slides. Each slide exposure using one of the three light primary colors, red, green, and blue in 1855. In 1975 Kodak engineer Steve Sassons invented the first digital camera. In 1976 Kodak engineer Bryce Bayer overlayed red, green, and blue filters in a matrix pattern on a digital image sensor. The Bayer Matrix filter pattern remains the leading method to generate a color picture in the digital camera.

If you think about this and a thousand other photographic advance you will discover how the camera and the materials of this art and science shape captured images so that when presented to the human eye, yield the yet unobtained “faithful image”. Today’s images are terrific, but know, the science marches on.

\$\endgroup\$
2
  • 3
    \$\begingroup\$ I do admire your encyclopaedic knowledge on matters such as this. I sometimes think your answers skirt answering the question directly but I do appreciate the insights. \$\endgroup\$
    – Tetsujin
    Commented Sep 17, 2021 at 15:39
  • \$\begingroup\$ It is the Bayer Matrix with its uneven distribution of red, green, and blue pixels that causes the digital sensor to closely match human color vision (color perception). \$\endgroup\$ Commented Sep 17, 2021 at 22:46

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.