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

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Original file (2,272 × 2,492 pixels, file size: 493 KB, MIME type: image/png)

Summary

Description
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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Public domain

This work is in the public domain in its country of origin and other countries and areas where the copyright term is the author's life plus 70 years or fewer.

You must also include a United States public domain tag to indicate why this work is in the public domain in the United States.
 Note that a few countries have copyright terms longer than 70 years: Mexico has 100 years, Jamaica has 95 years, Colombia has 80 years, and Guatemala and Samoa have 75 years. This image may not be in the public domain in these countries, which moreover do not implement the rule of the shorter term. Honduras has a general copyright term of 75 years, but it does implement the rule of the shorter term. Copyright may extend on works created by French who died for France in World War II (more information), Russians who served in the Eastern Front of World War II (known as the Great Patriotic War in Russia) and posthumously rehabilitated victims of Soviet repressions (more information).
This file has been identified as being free of known restrictions under copyright law, including all related and neighboring rights.
Other versions Version without highlighted noise: File:April 01-40N-2100-Fieldbook of Stars-025.jpg

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20c232332c15fb5eef973b8a72efebfb84a0e41d

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504,846 byte

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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{{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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