Re: [Gimp-user] Extracting images from a PDF
On Tue, 2019-09-24 at 18:25 +, dep wrote: > said Liam R E Quin: > > > To be clear, don't open the PDF in GIMP, as this will re-sample the > > image. > > Could you elaborate a bit here? Specifically, the harm you see coming > from this? If the PDF file contains a JPEG image that was encoded at 200dpi (say), and you open the PDF in GIMP at 300dpi, GIMP will use a library to render the PDF to a bitmap image at 300dpi, so that library will take the 200dpi embedded image, render it to a bitmap, and then enlarge it (artifacts of compression and all), probably using a simple linear or cubic interpolation. This means that every pixel in the image GIMP sees will be an average of the actual pixel values around it in the original. What you want to do is to extract the original 200dpi (in this example) image and then have GIMP open that, not lose the quality by changing the size first. There's no easy way to know the resolution of the embedded images; in some cases ImageMagick's "identify" command will list them, and e.g. https://superuser.com/questions/193485/extract-images-in-pdf-without-affecting-the-resolution links to a simple program to extract the actual JPEG images from PDF without reencoding them - https://www.perlmonks.org/?node_id=720495 If you just need to rotate them, you can then use e.g. jpegtran, which is lossless. Also note the free version of Acrobat also changes the sizes of the images by resampling. slave liam (ankh on IRC) -- https://www.fromoldbooks.org/ ___ gimp-user-list mailing list List address:gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list
Re: [Gimp-user] Extracting images from a PDF
said Liam R E Quin: | To be clear, don't open the PDF in GIMP, as this will re-sample the | image. Could you elaborate a bit here? Specifically, the harm you see coming from this? -- dep Some pictures: http://www.ipernity.com/doc/depscribe/album ___ gimp-user-list mailing list List address:gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list
Re: [Gimp-user] Extracting images from a PDF
On Tue, 2019-09-24 at 16:26 +, dep wrote: > The heritage of the PDF has something to do with it also. A lot of > PDFs are basically themselves a single image per page, in which case > you open it in the GIMP and crop it down to the image, To be clear, don't open the PDF in GIMP, as this will re-sample the image. > all the while weeping over the poor > quality of the thing, unless it's a very high resolution PDF. No? A lot depends on what you’re trying to accomplish. Sometimes i've used the Inkscape front end to “potrace” to make an SVG vector version of something, for example. And there've been times when i’ve bought a physical printed copy of a book so i can scan the images at 2400dpi. Liam (slave ankh) -- Liam Quin - web slave for https://www.fromoldbooks.org/ ___ gimp-user-list mailing list List address:gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list
Re: [Gimp-user] Extracting images from a PDF
2019年9月25日(水) 1:26 dep : > said Liam R E Quin: > | On Tue, 2019-09-24 at 17:51 +0200, Andrew-Yellow-Jackets wrote: > | > 1) I have an Adobe Acrobat license at work. I can go into edit mode, > | > pick the > | > image, then tell it to open with GIMP. > | > > | > 2) Open the PDF with Inkscape. > | > | On Linux™ systems you can also do this by opening the image in the > | GNOME Document Viewer (evince) and right-clicking Save Image. > > The heritage of the PDF has something to do with it also. A lot of PDFs > are > basically themselves a single image per page, in which case you open it in > the GIMP and crop it down to the image, which you save by whatever name > and in whatever format you want, :) all the while weeping over the poor > quality of the thing, unless it's a very high resolution PDF. No? > -- > dep > :-( Yeah. ___ gimp-user-list mailing list List address:gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list
Re: [Gimp-user] Extracting images from a PDF
said Liam R E Quin: | On Tue, 2019-09-24 at 17:51 +0200, Andrew-Yellow-Jackets wrote: | > 1) I have an Adobe Acrobat license at work. I can go into edit mode, | > pick the | > image, then tell it to open with GIMP. | > | > 2) Open the PDF with Inkscape. | | On Linux™ systems you can also do this by opening the image in the | GNOME Document Viewer (evince) and right-clicking Save Image. The heritage of the PDF has something to do with it also. A lot of PDFs are basically themselves a single image per page, in which case you open it in the GIMP and crop it down to the image, which you save by whatever name and in whatever format you want, all the while weeping over the poor quality of the thing, unless it's a very high resolution PDF. No? -- dep Some pictures: http://www.ipernity.com/doc/depscribe/album ___ gimp-user-list mailing list List address:gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list
Re: [Gimp-user] Extracting images from a PDF
On Tue, 2019-09-24 at 17:51 +0200, Andrew-Yellow-Jackets wrote: > > 1) I have an Adobe Acrobat license at work. I can go into edit mode, > pick the > image, then tell it to open with GIMP. > > 2) Open the PDF with Inkscape. On Linux™ systems you can also do this by opening the image in the GNOME Document Viewer (evince) and right-clicking Save Image. slave ankh -- web slave for https://www.fromoldbooks.org/ with fabulous vintage art and fascinating texts to read. Click here to order a new mouse pointer. ___ gimp-user-list mailing list List address:gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list
[Gimp-user] Extracting images from a PDF
I think OP wants the image without re-sampling. I've found two different ways to do this. 1) I have an Adobe Acrobat license at work. I can go into edit mode, pick the image, then tell it to open with GIMP. 1.5) Also with Acrobat, Save the PDF as Word, PowerPoint, etc., then grab the image out of the new document. 2) Open the PDF with Inkscape. It doesn't appear you can export individual images without having to specify a resolution. But it the PDF has more than one raster image, you can export them in bulk and it appears to use the original resolution. -- Andrew-Yellow-Jackets (via www.gimpusers.com/forums) ___ gimp-user-list mailing list List address:gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list
[Gimp-user] Extracting images from a PDF
>For what it's worth, if you have a lot of images buried in a PDF file, >extracting them all, one at a time, with the GIMP can be tedious. > >I generally use imagemagick to extract images from PDFs (imagemagick >convert). > > >2019年9月15日(日) 5:36 CaLy : Sorry to disturb you, i see two executables to download for 64bits (windows): 1) Win64 static at 16 bits-per-pixel component 2) Win64 dynamic at 8 bits-per-pixel component 3) Win64 static at 8 bits-per-pixel component 4) Win64 dynamic at 16 bits-per-pixel component with high dynamic-range imaging enabled Wich one should i download to extract the images from pdf? and btw it is from a command line in imagemagick right? Thanks ! -- CaLy (via www.gimpusers.com/forums) ___ gimp-user-list mailing list List address:gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list List archives: https://mail.gnome.org/archives/gimp-user-list
