{"id":1904,"date":"2015-06-27T20:00:46","date_gmt":"2015-06-27T18:00:46","guid":{"rendered":"http:\/\/www.tirages-pro.com\/blog\/?p=1904"},"modified":"2026-02-12T14:50:56","modified_gmt":"2026-02-12T13:50:56","slug":"la-compression-jpeg-comment-ca-marche","status":"publish","type":"post","link":"https:\/\/www.tirages-pro.com\/blog\/2015\/06\/la-compression-jpeg-comment-ca-marche\/","title":{"rendered":"La compression JPEG, comment \u00e7a marche ?"},"content":{"rendered":"\n<p>Le JPEG est l&rsquo;algorithme de compression le plus utilis\u00e9 lorsqu&rsquo;il s&rsquo;agit de stocker des images. <\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Comment fonctionne cet lalgorithme ?<\/li>\n\n\n\n<li>Comment arrive-t-on \u00e0 comprimer une image 10 x voire plus ? <\/li>\n\n\n\n<li>Sur quels ph\u00e9nom\u00e8nes physiques et sur\u00a0quelles fonctions\u00a0math\u00e9matiques cet algorithme se\u00a0base-t-il ?<\/li>\n\n\n\n<li>Et d&rsquo;ailleurs\u00a0les fichiers .jpg sont-ils bien des fichiers JPEG ?<\/li>\n<\/ul>\n\n\n\n<p>Toutes les r\u00e9ponses \u00e0 ces questions se trouvent dans les 2 excellentes videos suivantes,\u00a0propos\u00e9es par\u00a0la cha\u00eene\u00a0<a href=\"https:\/\/www.youtube.com\/user\/Computerphile\" target=\"_blank\" rel=\"noopener\">Computerphile<\/a>\u00a0qui vient de sortir une s\u00e9rie sur l&rsquo;algorithme de compression des fichiers JPEG.<\/p>\n\n\n\n<p>Tr\u00e8s techniques et en anglais, les 2 vid\u00e9os qui suivent sont cependant tr\u00e8s bien faites et valent vraiment le d\u00e9tour.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">La d\u00e9composition de la couleur<\/h2>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"JPEG &#039;files&#039; &amp; Colour (JPEG Pt1)- Computerphile\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/n_uNPbdenRs?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">La transformation cosinus discr\u00e8te, l&rsquo;algorithme de compression JPEG<\/h2>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"JPEG DCT, Discrete Cosine Transform (JPEG Pt2)- Computerphile\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/Q2aEzeMDHMA?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>Capable de diminuer la taille des fichiers de 10 x fois plus, comment fonctionne cet algorithme dans le d\u00e9tail ? 2 vid\u00e9os techniques d\u00e9cortiquent son fonctionnement.<\/p>\n","protected":false},"author":1,"featured_media":4927,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"none","_seopress_titles_title":"","_seopress_titles_desc":"","_seopress_robots_index":"","inline_featured_image":false,"_themeisle_gutenberg_block_has_review":false,"footnotes":""},"categories":[190],"tags":[142,143,141],"class_list":["post-1904","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-savoir","tag-compression","tag-fichiers","tag-jpeg"],"_links":{"self":[{"href":"https:\/\/www.tirages-pro.com\/blog\/wp-json\/wp\/v2\/posts\/1904","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.tirages-pro.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.tirages-pro.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.tirages-pro.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.tirages-pro.com\/blog\/wp-json\/wp\/v2\/comments?post=1904"}],"version-history":[{"count":9,"href":"https:\/\/www.tirages-pro.com\/blog\/wp-json\/wp\/v2\/posts\/1904\/revisions"}],"predecessor-version":[{"id":4925,"href":"https:\/\/www.tirages-pro.com\/blog\/wp-json\/wp\/v2\/posts\/1904\/revisions\/4925"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.tirages-pro.com\/blog\/wp-json\/wp\/v2\/media\/4927"}],"wp:attachment":[{"href":"https:\/\/www.tirages-pro.com\/blog\/wp-json\/wp\/v2\/media?parent=1904"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.tirages-pro.com\/blog\/wp-json\/wp\/v2\/categories?post=1904"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.tirages-pro.com\/blog\/wp-json\/wp\/v2\/tags?post=1904"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}