{"id":18015,"date":"2021-02-03T08:19:49","date_gmt":"2021-02-03T08:19:49","guid":{"rendered":"http:\/\/www.wjst.de\/blog\/?p=18015"},"modified":"2021-05-28T16:55:14","modified_gmt":"2021-05-28T16:55:14","slug":"isolated-vertical-or-horizontal-lines-in-gel-images-are-not-jpg-compression-artifacts","status":"publish","type":"post","link":"https:\/\/www.wjst.de\/blog\/sciencesurf\/2021\/02\/isolated-vertical-or-horizontal-lines-in-gel-images-are-not-jpg-compression-artifacts\/","title":{"rendered":"Isolated vertical or horizontal lines in gel images are not jpg compression artifacts"},"content":{"rendered":"<p>I frequently find the <a href=\"https:\/\/twitter.com\/MicrobiomDigest\/status\/1356722152741961729\">PubPeer excuse of compression artifacts<\/a> in doctored images.<\/p>\n<p>So lets have a look at that issue using the <a href=\"http:\/\/macappstore.org\/jpegoptim\/\">jpegoptim<\/a> (<a href=\"https:\/\/www.systutorials.com\/docs\/linux\/man\/1-jpegoptim\/\">manpage<\/a>) and also <a href=\"http:\/\/macappstore.org\/jpeginfo\/\">jpeginfo<\/a> (<a href=\"https:\/\/www.unix.com\/man-page\/debian\/1\/JPEGINFO\/\">manpage<\/a>). These are the usual effects<\/p>\n<ul>\n<li>Ringing &#8211; high contrast areas with waves<\/li>\n<li>Contouring, Banding, Pposterisation &#8211; extreme brightness changes<\/li>\n<li>Staircase noise &#8211; along curving edges<\/li>\n<li>Blockiness in &#8220;busy&#8221; regions &#8211; may mimick duplications<\/li>\n<li>Gibbs phenomenon &#8211; small highlighted area of large contrast<\/li>\n<li>Alias, Moir\u00e9, frequent color\/brightness change<\/li>\n<\/ul>\n<p>Now let&#8217;s have a look at the compression artifacts in descending quality (BTW this also good exercise for the upcoming 125kB Content Upload Filter, I am therefore adding\u00a0 filesize also)<\/p>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_18025\" aria-describedby=\"caption-attachment-18025\" style=\"width: 620px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i100.jpg\" data-rel=\"key-image-0\" data-rl_title=\"\" data-rl_caption=\"\" title=\"\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-18025 size-medium\" src=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i100-620x496.jpg\" alt=\"\" width=\"620\" height=\"496\" srcset=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i100-620x496.jpg 620w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i100-625x500.jpg 625w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i100-768x614.jpg 768w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i100.jpg 1024w\" sizes=\"auto, (max-width: 620px) 100vw, 620px\" \/><\/a><figcaption id=\"caption-attachment-18025\" class=\"wp-caption-text\">original image 893kB<\/figcaption><\/figure>\n<p><!--more--><\/p>\n<figure id=\"attachment_18024\" aria-describedby=\"caption-attachment-18024\" style=\"width: 620px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i64.jpg\" data-rel=\"key-image-1\" data-rl_title=\"\" data-rl_caption=\"\" title=\"\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-18024 size-medium\" src=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i64-620x496.jpg\" alt=\"\" width=\"620\" height=\"496\" srcset=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i64-620x496.jpg 620w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i64-625x500.jpg 625w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i64-768x614.jpg 768w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i64.jpg 1024w\" sizes=\"auto, (max-width: 620px) 100vw, 620px\" \/><\/a><figcaption id=\"caption-attachment-18024\" class=\"wp-caption-text\">maximum image quality factor 64% 172kB<\/figcaption><\/figure>\n<figure id=\"attachment_18023\" aria-describedby=\"caption-attachment-18023\" style=\"width: 620px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i32.jpg\" data-rel=\"key-image-2\" data-rl_title=\"\" data-rl_caption=\"\" title=\"\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-18023 size-medium\" src=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i32-620x496.jpg\" alt=\"\" width=\"620\" height=\"496\" srcset=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i32-620x496.jpg 620w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i32-625x500.jpg 625w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i32-768x614.jpg 768w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i32.jpg 1024w\" sizes=\"auto, (max-width: 620px) 100vw, 620px\" \/><\/a><figcaption id=\"caption-attachment-18023\" class=\"wp-caption-text\">maximum image quality factor 32% 105kB<\/figcaption><\/figure>\n<figure id=\"attachment_18022\" aria-describedby=\"caption-attachment-18022\" style=\"width: 620px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i16.jpg\" data-rel=\"key-image-3\" data-rl_title=\"\" data-rl_caption=\"\" title=\"\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-18022 size-medium\" src=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i16-620x496.jpg\" alt=\"\" width=\"620\" height=\"496\" srcset=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i16-620x496.jpg 620w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i16-625x500.jpg 625w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i16-768x614.jpg 768w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i16.jpg 1024w\" sizes=\"auto, (max-width: 620px) 100vw, 620px\" \/><\/a><figcaption id=\"caption-attachment-18022\" class=\"wp-caption-text\">maximum image quality factor 16% 65kB<\/figcaption><\/figure>\n<figure id=\"attachment_18021\" aria-describedby=\"caption-attachment-18021\" style=\"width: 620px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i8.jpg\" data-rel=\"key-image-4\" data-rl_title=\"\" data-rl_caption=\"\" title=\"\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-18021 size-medium\" src=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i8-620x496.jpg\" alt=\"\" width=\"620\" height=\"496\" srcset=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i8-620x496.jpg 620w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i8-625x500.jpg 625w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i8-768x614.jpg 768w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i8.jpg 1024w\" sizes=\"auto, (max-width: 620px) 100vw, 620px\" \/><\/a><figcaption id=\"caption-attachment-18021\" class=\"wp-caption-text\">maximum image quality factor 8% 38kB<\/figcaption><\/figure>\n<figure id=\"attachment_18020\" aria-describedby=\"caption-attachment-18020\" style=\"width: 620px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i4.jpg\" data-rel=\"key-image-5\" data-rl_title=\"\" data-rl_caption=\"\" title=\"\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-18020 size-medium\" src=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i4-620x496.jpg\" alt=\"\" width=\"620\" height=\"496\" srcset=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i4-620x496.jpg 620w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i4-625x500.jpg 625w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i4-768x614.jpg 768w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i4.jpg 1024w\" sizes=\"auto, (max-width: 620px) 100vw, 620px\" \/><\/a><figcaption id=\"caption-attachment-18020\" class=\"wp-caption-text\">maximum image quality factor 4% 23KB<\/figcaption><\/figure>\n<figure id=\"attachment_18019\" aria-describedby=\"caption-attachment-18019\" style=\"width: 620px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i3.jpg\" data-rel=\"key-image-6\" data-rl_title=\"\" data-rl_caption=\"\" title=\"\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-18019 size-medium\" src=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i3-620x496.jpg\" alt=\"\" width=\"620\" height=\"496\" srcset=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i3-620x496.jpg 620w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i3-625x500.jpg 625w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i3-768x614.jpg 768w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i3.jpg 1024w\" sizes=\"auto, (max-width: 620px) 100vw, 620px\" \/><\/a><figcaption id=\"caption-attachment-18019\" class=\"wp-caption-text\">maximum image quality factor 3% 19kB<\/figcaption><\/figure>\n<figure id=\"attachment_18018\" aria-describedby=\"caption-attachment-18018\" style=\"width: 620px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i2.jpg\" data-rel=\"key-image-7\" data-rl_title=\"\" data-rl_caption=\"\" title=\"\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-18018 size-medium\" src=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i2-620x496.jpg\" alt=\"\" width=\"620\" height=\"496\" srcset=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i2-620x496.jpg 620w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i2-625x500.jpg 625w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i2-768x614.jpg 768w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i2.jpg 1024w\" sizes=\"auto, (max-width: 620px) 100vw, 620px\" \/><\/a><figcaption id=\"caption-attachment-18018\" class=\"wp-caption-text\">maximum image quality factor 2% 18kB<\/figcaption><\/figure>\n<figure id=\"attachment_18017\" aria-describedby=\"caption-attachment-18017\" style=\"width: 620px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i1.jpg\" data-rel=\"key-image-8\" data-rl_title=\"\" data-rl_caption=\"\" title=\"\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-18017 size-medium\" src=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i1-620x496.jpg\" alt=\"\" width=\"620\" height=\"496\" srcset=\"https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i1-620x496.jpg 620w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i1-625x500.jpg 625w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i1-768x614.jpg 768w, https:\/\/www.wjst.de\/blog\/wp-content\/uploads\/2021\/02\/i1.jpg 1024w\" sizes=\"auto, (max-width: 620px) 100vw, 620px\" \/><\/a><figcaption id=\"caption-attachment-18017\" class=\"wp-caption-text\">maximum image quality factor 1% 18kB<\/figcaption><\/figure>\n<p>Maybe the most frequent issue that I see in published PDFs is the 4% or 8% blockiness in the shadow area.<\/p>\n<p>Issues like sharp vertical or horizontal lines in images of gel blots are no compression artifacts but due to to rectangle selections from copied image areas.<\/p>\n\n<p>&nbsp;<\/p>\n<div class=\"bottom-note\">\n  <span class=\"mod1\">CC-BY-NC Science Surf , accessed 24.04.2026<\/span>\n <\/div>","protected":false},"excerpt":{"rendered":"<p>I frequently find the PubPeer excuse of compression artifacts in doctored images. So lets have a look at that issue using the jpegoptim (manpage) and also jpeginfo (manpage). These are the usual effects Ringing &#8211; high contrast areas with waves Contouring, Banding, Pposterisation &#8211; extreme brightness changes Staircase noise &#8211; along curving edges Blockiness in &hellip; <a href=\"https:\/\/www.wjst.de\/blog\/sciencesurf\/2021\/02\/isolated-vertical-or-horizontal-lines-in-gel-images-are-not-jpg-compression-artifacts\/\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">Isolated vertical or horizontal lines in gel images are not jpg compression artifacts<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[3044,3621,1661,3523,3620],"class_list":["post-18015","post","type-post","status-publish","format-standard","hentry","category-philosophy-of-science","tag-eu","tag-filter","tag-forensics","tag-image","tag-upload"],"_links":{"self":[{"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/posts\/18015","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/comments?post=18015"}],"version-history":[{"count":11,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/posts\/18015\/revisions"}],"predecessor-version":[{"id":18454,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/posts\/18015\/revisions\/18454"}],"wp:attachment":[{"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/media?parent=18015"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/categories?post=18015"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wjst.de\/blog\/wp-json\/wp\/v2\/tags?post=18015"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}