{"action":"created","issue":{"url":"https://api.github.com/repos/aperto/PDFrenderer/issues/6","labels_url":"https://api.github.com/repos/aperto/PDFrenderer/issues/6/labels{/name}","comments_url":"https://api.github.com/repos/aperto/PDFrenderer/issues/6/comments","events_url":"https://api.github.com/repos/aperto/PDFrenderer/issues/6/events","html_url":"https://github.com/aperto/PDFrenderer/issues/6","id":55908522,"number":6,"title":"Update the testcode to be less dependent of platform based rendering","user":{"login":"costamojan","id":9274688,"avatar_url":"https://avatars.githubusercontent.com/u/9274688?v=3","gravatar_id":"","url":"https://api.github.com/users/costamojan","html_url":"https://github.com/costamojan","followers_url":"https://api.github.com/users/costamojan/followers","following_url":"https://api.github.com/users/costamojan/following{/other_user}","gists_url":"https://api.github.com/users/costamojan/gists{/gist_id}","starred_url":"https://api.github.com/users/costamojan/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/costamojan/subscriptions","organizations_url":"https://api.github.com/users/costamojan/orgs","repos_url":"https://api.github.com/users/costamojan/repos","events_url":"https://api.github.com/users/costamojan/events{/privacy}","received_events_url":"https://api.github.com/users/costamojan/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2015-01-29T14:54:13Z","updated_at":"2015-01-29T16:49:52Z","closed_at":null,"body":"At the moment the comparison of images used for testing is based on an exact equivalence of pixels. This might be hardware specific due to graphic charasteristics of the targeted machine.\r\nSince we're only interested to know wether a certain character is contained or not we should rework the tests to perform some sort of text extraction (probably OCR based)."},"comment":{"url":"https://api.github.com/repos/aperto/PDFrenderer/issues/comments/72059551","html_url":"https://github.com/aperto/PDFrenderer/issues/6#issuecomment-72059551","issue_url":"https://api.github.com/repos/aperto/PDFrenderer/issues/6","id":72059551,"user":{"login":"costamojan","id":9274688,"avatar_url":"https://avatars.githubusercontent.com/u/9274688?v=3","gravatar_id":"","url":"https://api.github.com/users/costamojan","html_url":"https://github.com/costamojan","followers_url":"https://api.github.com/users/costamojan/followers","following_url":"https://api.github.com/users/costamojan/following{/other_user}","gists_url":"https://api.github.com/users/costamojan/gists{/gist_id}","starred_url":"https://api.github.com/users/costamojan/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/costamojan/subscriptions","organizations_url":"https://api.github.com/users/costamojan/orgs","repos_url":"https://api.github.com/users/costamojan/repos","events_url":"https://api.github.com/users/costamojan/events{/privacy}","received_events_url":"https://api.github.com/users/costamojan/received_events","type":"User","site_admin":false},"created_at":"2015-01-29T16:49:52Z","updated_at":"2015-01-29T16:49:52Z","body":"I've tried several open source solutions within the past hours but none of those was reliable (I've used the current test pdf for my experiments):\r\n\r\n* Java OCR (see http://sourceforge.net/projects/javaocr) generates a lot of misses. It often detects simple pixel fragments as characters rendering the overall scanning process useless. There is a training mode which I didn't use as it would require to generate varieties of our test candidate in order to pass them. Furthermore the software description doesn't provide any information about the used scanning techniques (f.e. statistical analysis, picture manipulation etc.). Apart from that it would be necessary to incorporate this tool as a library.\r\n\r\n* Tesseract (see https://code.google.com/p/tesseract-ocr/) is supposed to be one of the best OCR implementations. It's available as a commandline and could therefore be integrated as part of a test. Apart from that it provides language specific presets for statistical word analysis in order to recognize character sequence. Unfortunately the image which had been generated using the PDF didn not work as most of the detected letters were garbage.\r\n\r\nI suggest to just live with the fact that we might have differences on different machines. We only need to make sure that the generated expected images will be rendered at the machine under test.\r\n"}}