Commons:Featured picture candidates/removal/File:Centaur mosaic - Google Art Project retouched.jpeg

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Voting period is over. Please don't add any new votes.Voting period ends on 10 May 2019 at 05:43:52
Centaur mosaic - Google Art Project Proposal replacement

  •  Delist and replace I took the original 4 GAP tiles that provide the highest resolution version and assembled them in Photoshop. Saved this locally as a TIF (2GB). Cropped out the black frame. Added an exposure adjustment layer with +1ev (i.e., one stop brighter). Saved copies of this as three JPGs at different resolutions, with sRGB colour profile, quality level 10 of 12. For the largest file (nominated here) I can download it in Firefox and view it brower-sized but when I click to magnify to 1:1 then Firefox just shows a blurry temporary image while trying to render it. Eventually it seems to give up and show black. Sometimes also for very large images, it will show black for a while but will eventually display the image. I think Browsers aren't really meant to be used as viewers for gigapixel images. It works just fine in Photoshop and other quality image tools. The Zoom viewer works fine and can be used to examine the detail.
The difference between this and the previous nomination is size (1.3 gigapixel vs 500 megapixel) and how it was brightened. I used a Photoshop exposure adjustment layer and did not alter the colour balance (temperature). The previous nomination was altered by eye for temperature, brightness and contrast by adjusting the red/green/blue channels. Since we have no reference for how warm-toned this image should be, I think it best to assume the original photographers calibrated their work. I'm not sure why the GAP original was dark (other photographs and video of this work don't appear as dark), though it doesn't appear as dark when you remove the black frame. As mentioned in the previous nom, this artwork is only a remaining portion of a larger floor mosaic, so black frame was modern. -- Colin (talk) 08:59, 1 May 2019 (UTC)[reply]
  •  Delist and replace -- 🇪🅰〒ℂ🇭🅰- 💬 10:14, 1 May 2019 (UTC)[reply]
  •  Delist and replace - Thank you for explaining, Colin. It sounds like the ideal thing would be to edit the photo while standing in front of that floor, to check on the actual colors and tones in situ. In the meantime, though, your work is absolutely gorgeous (based on the 12k width version, which is plenty big enough for me). -- Ikan Kekek (talk) 10:18, 1 May 2019 (UTC)[reply]
    • Ikan, the pros use a ColorChecker card that is photographed along with the artwork. The main purpose is to calibrate the colours and the hue of neutral white/grey which can vary depending on what light source is used. It can also be used to adjust exposure so I'm not clear why the original is dark. A computer monitor can also be calibrated with a device placed on the screen while lots of different colours are displayed in sequence. This also requires the image view/edit software used to respect that calibration. It is quite hard to compare by eye, but we have the tools to do it accurately. For example, the brightness you see on your monitor, and your ability to distinguish the really dark shades, is influenced also by how bright your room is, and whether there is a light source (window) behind your monitor. Your impression about whether an image here is too warm or to cold is also influenced by your monitor settings and whether you are viewing just the photo or have it as a thumb surrounded by "white". See also The dress and this illusion. Laptops usually have poor quality screens, even expensive ones. This is why I think we should try where possible to retain the image produced by the professionals, though I'm sure they make mistakes too. -- Colin (talk) 10:57, 1 May 2019 (UTC)[reply]
Result: 14 delist, 0 keep, 0 neutral => delisted and replaced. --A.Savin 02:17, 11 May 2019 (UTC)[reply]