{"id":303,"date":"2009-01-13T20:11:35","date_gmt":"2009-01-14T00:11:35","guid":{"rendered":"http:\/\/scott.sherrillmix.com\/blog\/?p=303"},"modified":"2009-06-10T03:34:00","modified_gmt":"2009-06-10T07:34:00","slug":"converting-eps-to-png-easily","status":"publish","type":"post","link":"http:\/\/scott.sherrillmix.com\/blog\/programmer\/converting-eps-to-png-easily\/","title":{"rendered":"Converting .eps to .png Easily"},"content":{"rendered":"<p>I end up generating a lot of postscript plots in R and other programs. Unfortunately, a lot of not so technical people have trouble opening postscript files so I end up having to convert these images to other formats pretty often. A really handy program for converting eps files to png (or jpg although that&#8217;s not really an optimal format for plots) is <a href='http:\/\/www.imagemagick.org\/'>ImageMagick<\/a> (available for all OSs I believe). ImageMagick lets you quickly convert (and <a href='http:\/\/www.imagemagick.org\/Usage\/'>create thumbnails, make B&#038;W,&#8230;<\/a>) from the command line without having to open up Photoshop.<\/p>\r\n<p>For example, to convert an image named myPlot.eps to png you just need to enter <code>convert myPlot.eps myPlot.png<\/code> (convert is a program in the ImageMagick package) at the command prompt and you&#8217;ll get a png file in myPlot.png. If you want to adjust the resolution (the default resolution is 72 dpi) of the output image, you can add the <code>-density<\/code> option (e.g. for 200 dpi <code>convert -density 200 myPlot.eps myPlot.png<\/code>). Make sure you put the <code>-density<\/code> part before the input image name.<\/p>\r\n<p>Converting many files at once is where ImageMagick really shines. The <code>mogrify<\/code> command is probably the quickest option. For example, to convert the files image01.eps, image02.eps and image03.eps to png, just use the command <code>mogrify -format png image*.eps<\/code>. In one shot, it will create image01.png, image02.png and image03.png.<\/p> \r\n\r\n<p>Unfortunately, recent version of Imagemagick seem to be treating eps to png conversions oddly (see below) so mogrify isn&#8217;t cutting it on my files. If you have similar trouble (and you&#8217;re on Unix or Mac or Cygwin), you can just use a bit of Bash combined with the <code>convert<\/code> command to get around the problem like this:<\/p>\r\n[bash]\r\nfor f in `ls *.eps`; do \r\n     convert -density 100 $f -flatten ${f%.*}.png;\r\ndone\r\n[\/bash]\r\n\r\n<h4>Black Background Problem<\/h4>\r\n<p>As I mentioned above, I started having trouble converting from eps to png after upgrading to ImageMagick 6.4. The transparent\/white backgrounds in my eps files were being converted to black backgrounds and making the figures unreadable. I guess it must be some change in how transparency is handled but I&#8217;m not totally sure what changed. It took me a bit of googling before I found the <a href='http:\/\/www.nabble.com\/Background-issue-converting-.eps-to-.png-td20094851.html'>solution<\/a>, so I&#8217;ll repost it here. Adding <code>-flatten<\/code> to the command (e.g. <code>convert myImage.eps -flatten myImage.png<\/code>) should change the background back to white. My <code>mogrify<\/code> command doesn&#8217;t include the <code>-flatten<\/code> option so <code>convert<\/code> (like the example above) seems like the way to go.<\/p>","protected":false},"excerpt":{"rendered":"I end up generating a lot of postscript plots in R and other programs. Unfortunately, a lot of not so technical people have trouble opening postscript files so I end up having to convert these images to other formats pretty often. A really handy program for converting eps files to png (or jpg although that&#8217;s [&hellip;]","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6,5],"tags":[415,73,414,411,408,690,412,413,410,409,99],"_links":{"self":[{"href":"http:\/\/scott.sherrillmix.com\/blog\/wp-json\/wp\/v2\/posts\/303"}],"collection":[{"href":"http:\/\/scott.sherrillmix.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/scott.sherrillmix.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/scott.sherrillmix.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/scott.sherrillmix.com\/blog\/wp-json\/wp\/v2\/comments?post=303"}],"version-history":[{"count":17,"href":"http:\/\/scott.sherrillmix.com\/blog\/wp-json\/wp\/v2\/posts\/303\/revisions"}],"predecessor-version":[{"id":487,"href":"http:\/\/scott.sherrillmix.com\/blog\/wp-json\/wp\/v2\/posts\/303\/revisions\/487"}],"wp:attachment":[{"href":"http:\/\/scott.sherrillmix.com\/blog\/wp-json\/wp\/v2\/media?parent=303"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/scott.sherrillmix.com\/blog\/wp-json\/wp\/v2\/categories?post=303"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/scott.sherrillmix.com\/blog\/wp-json\/wp\/v2\/tags?post=303"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}