Better image quality for doc view?

Better image quality for doc view?

[xiongtk]

The default doc view is not comparable in terms of quality of display
to other professional pdf viewers. But I want to at least see the words
clearly when I fit the document to half of my screen while I work on the
other half. I would like to ask for advises on how to improve the
display quality.

I've tried to change 'doc-view-resolution, but it only make the default
image larger in size. The quality looks the same when re-sized. Should I
change the program that converts PDF files to PNG?

Thanks in advance!

Re: Better image quality for doc view?

[Marcin Borkowski]

On 2016-05-29, at 20:12, xiongtk <xiongtk@gmail.com> wrote:

> The default doc view is not comparable in terms of quality of display
> to other professional pdf viewers. But I want to at least see the words
> clearly when I fit the document to half of my screen while I work on the
> other half. I would like to ask for advises on how to improve the
> display quality.
>
> I've tried to change 'doc-view-resolution, but it only make the default
> image larger in size. The quality looks the same when re-sized. Should I
> change the program that converts PDF files to PNG?
>
> Thanks in advance!

Have you tried pdf-tools?
https://github.com/politza/pdf-tools

Hth,

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University

Re: Better image quality for doc view?

[xiongtk]

Marcin Borkowski <mbork@mbork.pl> writes:

> On 2016-05-29, at 20:12, xiongtk <xiongtk@gmail.com> wrote:
>
>> The default doc view is not comparable in terms of quality of display
>> to other professional pdf viewers. But I want to at least see the words
>> clearly when I fit the document to half of my screen while I work on the
>> other half. I would like to ask for advises on how to improve the
>> display quality.
>>
>> I've tried to change 'doc-view-resolution, but it only make the default
>> image larger in size. The quality looks the same when re-sized. Should I
>> change the program that converts PDF files to PNG?
>>
>> Thanks in advance!
>
> Have you tried pdf-tools?
> https://github.com/politza/pdf-tools
>
> Hth,
I've just installed it. The quality is better, but some files are not
correctly converted(certain sentences are missing). I found that it does
not officially support OS X.

Re: Better image quality for doc view?

[YAMAMOTO Mitsuharu]

xiongtk <xiongtk <at> gmail.com> writes:

> 
> Marcin Borkowski <mbork <at> mbork.pl> writes:
> 
> > On 2016-05-29, at 20:12, xiongtk <xiongtk <at> gmail.com> wrote:
> >
> >> The default doc view is not comparable in terms of quality of display
> >> to other professional pdf viewers. But I want to at least see the words
> >> clearly when I fit the document to half of my screen while I work on the
> >> other half. I would like to ask for advises on how to improve the
> >> display quality.
> >>
> >> I've tried to change 'doc-view-resolution, but it only make the default
> >> image larger in size. The quality looks the same when re-sized. Should I
> >> change the program that converts PDF files to PNG?
> >>
> >> Thanks in advance!
> >
> > Have you tried pdf-tools?
> > https://github.com/politza/pdf-tools
> >
> > Hth,
> I've just installed it. The quality is better, but some files are not
> correctly converted(certain sentences are missing). I found that it does
> not officially support OS X.

Are you using some Retina display model?  Then, which Emacs are
you using on OS X?

The NS port, which is bundled with the standard Emacs
distribution, always displays images with magnification and
interpolation because of lack of high-resolution image display
support.  As a result, all the images look blurry compared with
the surrounding text on a Retina display.

The Mac port, which is distributed separately from the standard
distribution, has high-resolution image display support.  Also,
it modifies DocView mode so it asks external programs such as
ghostscript to generate large images for high-resolution
environments.

  https://bitbucket.org/mituharu/emacs-
mac/src/7ab812f134e21ebbca355462888bfc2da4703a57/doc/emacs/macport.texi?
at=master&fileviewer=file-view-default#macport.texi-447

If you want to try the Mac port, there's a precompiled binary
package: https://github.com/railwaycat/homebrew-emacsmacport/releases

				     YAMAMOTO Mitsuharu
				mituharu@math.s.chiba-u.ac.jp

Re: Better image quality for doc view?

[xiongtk]

> Are you using some Retina display model?  Then, which Emacs are
> you using on OS X?
>
Yes, I'm using a retina display MBP. The Emacs I'm using is 24.5,
compiled with Homebrew.


> The NS port, which is bundled with the standard Emacs
> distribution, always displays images with magnification and
> interpolation because of lack of high-resolution image display
> support.  As a result, all the images look blurry compared with
> the surrounding text on a Retina display.
>
> The Mac port, which is distributed separately from the standard
> distribution, has high-resolution image display support.  Also,
> it modifies DocView mode so it asks external programs such as
> ghostscript to generate large images for high-resolution
> environments.
>
>   https://bitbucket.org/mituharu/emacs-
> mac/src/7ab812f134e21ebbca355462888bfc2da4703a57/doc/emacs/macport.texi?
> at=master&fileviewer=file-view-default#macport.texi-447
>
> If you want to try the Mac port, there's a precompiled binary
> package: https://github.com/railwaycat/homebrew-emacsmacport/releases
Great! I'll give it a try.
>
> 				     YAMAMOTO Mitsuharu
> 				mituharu@math.s.chiba-u.ac.jp

Re: Better image quality for doc view?

[Stefan Monnier]

> Should I change the program that converts PDF files to PNG?

Sounds like it, yes,


        Stefan

Re: Better image quality for doc view?

[Tassilo Horn]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> Should I change the program that converts PDF files to PNG?
>
> Sounds like it, yes,

Doc-view uses GhostScript which is basically installed anywhere but if
mupdf is installed on your system, too, it'll instead use that (no need
to tweak some option).  I'm not sure if that gives better quality but
for sure it is way faster.

You can see what it currently uses by checking the value of
`doc-view-pdf->png-converter-function'.

Bye,
Tassilo

Re: Better image quality for doc view?

[xiongtk]

Tassilo Horn <tsdh@gnu.org> writes:

> Stefan Monnier <monnier@iro.umontreal.ca> writes:
>
>>> Should I change the program that converts PDF files to PNG?
>>
>> Sounds like it, yes,
>
> Doc-view uses GhostScript which is basically installed anywhere but if
> mupdf is installed on your system, too, it'll instead use that (no need
> to tweak some option).  I'm not sure if that gives better quality but
> for sure it is way faster.
>
> You can see what it currently uses by checking the value of
> `doc-view-pdf->png-converter-function'.
>
> Bye,
> Tassilo
I've just tried that. But before that I have started using pdf-tools. To
me these two have little difference in quality. And each of them show me
certain lack of fidelity with different files. Your solution is a bit
better to me as the initiation time is faster.

Re: Better image quality for doc view?

[Joost Kremers]

xiongtk wrote:
> The default doc view is not comparable in terms of quality of display
> to other professional pdf viewers. But I want to at least see the words
> clearly when I fit the document to half of my screen while I work on the
> other half. I would like to ask for advises on how to improve the
> display quality.
>
> I've tried to change 'doc-view-resolution, but it only make the default
> image larger in size. The quality looks the same when re-sized. Should I
> change the program that converts PDF files to PNG?

You'll probably be better off trying pdf-tools:

https://github.com/politza/pdf-tools

-- 
Joost Kremers                                   joostkremers@fastmail.fm
Selbst in die Unterwelt dringt durch Spalten Licht
EN:SiS(9)