Re: Auto-resizing of images in image-mode

[Alan Third]

On Sun, Apr 19, 2020 at 02:45:18AM +0300, Juri Linkov wrote:
> >> It's impossible to view an image in its original size even without this 
> >> feature.
> >> A few years ago image-mode was changed to resize the image to fit in the
> >> window when visiting an image file.
> >
> > Maybe so, but Emacs 26 still shows the images in their original size,
> > AFAICT.  So this is new in Emacs 27, at least for me.  I think that's
> > because previously the automatic resizing worked only in Emacs built
> > with ImageMagick, whereas in Emacs 27 we can resize natively.  I build
> > my Emacs without ImageMagick, and I wonder how many others do, due to
> > ImageMagick's instability.
> 
> I'm not sure how it could be new in Emacs 27 because
> image-transform-resize was added in year 2014.

Before Emacs 27 any image scaling and rotation required imagemagick.
Emacs 27 can (mostly) handle it without imagemagick now. So yes, this
behaviour is new to people who don’t build with imagemagick.

> But anyway their docstrings say:
> 
>   This command has no effect unless Emacs is compiled with
>   ImageMagick support.
> 
> So these commands should be fixed to work without ImageMagick.

It should generally be a case of removing any checks for imagemagick
since the dependence on it is no longer there. In some cases I think
the docstring says it relies on imagemagick, but the function works in
Emacs 27 without it anyway.

-- 
Alan Third