File:April 01-40N-2100-Fieldbook of Stars-025 - JPEG noise.png

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English: A demonstration of the presence of JPG noise in a black and white image. Generation process (starting with sm.png and sm.jpg, which is saved from the PNG with quality=90):
convert sm.jpg sm.png -compose minus -composite -negate -threshold 99% -fill red -opaque black -transparent white diff.png
convert sm.png result.png -composite out.png
Date 1907, edited 2021
Source File:April 01-40N-2100-Fieldbook of Stars-025.jpg
Author William Tyler Olcott
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Other versions Version without highlighted noise: File:April 01-40N-2100-Fieldbook of Stars-025.jpg

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Date/TimeThumbnailDimensionsUserComment
current17:34, 10 February 2021Thumbnail for version as of 17:34, 10 February 20212,272 × 2,492 (493 KB)Inductiveload (talk | contribs){{Information |Description={{en|1=A demonstration of the presence of JPG noise in a black and white image. Generation process (starting with sm.png and sm.jpg, which is saved from the PNG): <pre> convert sm.jpg sm.png -compose minus -composite -negate -threshold 99% -fill red -opaque black -transparent white diff.png convert sm.png result.png -composite out.png </pre> }} |Source=File:April 01-40N-2100-Fieldbook of Stars-025.jpg |Date=1907, edited 2021 |Author=William Tyler Olcott |Per...

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