| | <<<Back 1 day (to 2016/06/11) | 20160612 |
| freelery | hi | 16:21.17 |
| ghostbot | Welcome to #ghostscript, the channel for Ghostscript and MuPDF. If you have a question, please ask it, don't ask to ask it. Do be prepared to wait for a reply as devs will check the logs and reply when they come on line. | 16:21.17 |
| freelery | i need some help for converting PDF to JPG | 16:21.35 |
| | the quality sucks or the file size is too big | 16:21.49 |
| | best command so far: | 16:22.53 |
| | gs -dNOPAUSE -sDEVICE=png16m -dFirstPage=1 -dLastPage=33 -sOutputFile=ptolus01-%d.jpg -dJPEGQ=100 -dDownScaleFactor=2 -r350 -q ptolus.pdf -c quit | 16:22.55 |
| | which boost the imagefile to 70mb from 11mb PDF | 16:23.12 |
| Robin_Watts | freelery: Well, that's not producing a jpeg. | 16:32.43 |
| | That's producing a png. | 16:32.49 |
| | freelery: First off, are you sure you want to be making a jpeg? | 16:33.24 |
| | jpeg's are great for representing contone images like photographs. | 16:33.40 |
| | They suck massively for representing text or line art. | 16:33.58 |
| | If you REALLY want to be producing a jpeg then you want either -sDEVICE=jpeg, or -sDEVICE=jpeggray, or -sDEVICE=jpegcmyk. | 16:35.41 |
| | So before we go any further, what sort of content do you have on the page, and what are you doing with the jpeg when you've got it?> | 16:36.20 |
| freelery | Robin_Watts, but the jpeg device produces crap | 16:41.08 |
| | yes i need JPG, because i want to make a CBR | 16:41.22 |
| | sooo Robin_Watts?? | 16:58.46 |
| Robin_Watts | What sort of content on the page? | 16:59.32 |
| | Text? Line Art? contone bitmap images? | 17:00.17 |
| freelery | its a comic | 17:02.09 |
| | i have now used pdfimages, i get perfect jpgs's, just extracted, but the dialogs missing :P | 17:02.38 |
| Robin_Watts | If your intent is to produce something for screen use (i.e. you're going to view it a screen, rather than print it out), then I'd be tempted to say you should get a .PNG out from gs, and then use a separate program to recompress those. | 17:03.09 |
| | Personally I reckon you probably want the text anti-aliased too. | 17:03.36 |
| | If you go the png -> cbz routine, then I'd use gs -sDEVICE=png16m -o out.png -dDownScaleFactor=3 -r=475 | 17:04.52 |
| | That will produce you pngs in as high quality as you could possibly hope for. | 17:05.04 |
| | Then I'd use pngcrush (or something like that) to recompress the PNGs losslessly to something small. | 17:05.28 |
| freelery | okay, as i see, i also can use PNG for CBR format, so i try again | 17:07.37 |
| Robin_Watts | If you really must use jpeg, then accept the fact that your text will look awful, and use a jpeg compressor to convert from png in a post step. | 17:07.37 |
| freelery | but they grow soo much bigger than PDF, it's abnorm | 17:07.46 |
| Robin_Watts | freelery: Of course they do. | 17:08.02 |
| | the PDF is the JPEG, plus a list of the text to overlay. | 17:08.22 |
| | Once that's overlaid there is WAY more high res detail in the JPEGs to cope with. | 17:08.41 |
| | And gs makes no effort to compress the pngs well. | 17:08.51 |
| | That's what pngcrush will do for you. | 17:09.01 |
| freelery | thank you very much, looks good so far | 17:10.07 |
| | what command do you use for pngcrush? | 17:10.16 |
| | Robin_Watts, pngcrush brings 0% compression | 17:35.21 |
| | okay maybe 2% :/ | 17:35.57 |
| Robin_Watts | pngcrush -brute infile.png out.png | 17:36.02 |
| freelery | yeah i did brute | 17:36.10 |
| | so i am ending up with 58mb vs. 11mb pdf | 17:36.43 |
| Robin_Watts | Yeah. | 17:37.48 |
| | pngcrush -brute -reduce -l 9 -loco ? | 17:38.45 |
| freelery | no just brute | 17:50.21 |
| Robin_Watts | We produce 24bit PNGs. i.e. truecolor ones | 17:55.51 |
| | --reduce might help with that. | 17:56.00 |
| | likewise -loco | 17:56.06 |
| | marcosw: ping | 22:53.48 |
| | Forward 1 day (to 2016/06/13)>>> | |
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