Starting in pandoc 2, figures without captions are left-justified in PDF output

[nsheff]

I am producing PDF output from markdown source.

In pandoc 1, figures without captions were centered by default. In pandoc 2, figures without captions are left-justified.

Was this change intended? I did not see documentation of this change in the release notes. I believe this is a bug and figures without captions should be centered in pandoc 2.

Reproducible example:

image.md:

# Here's an image:

![](example_figure.png)

example_figure.png:

command: `pandoc image.md -o image.pdf

Result under pandoc1: image.pdf

Result under pandoc2: image-pandoc2.pdf

[jgm]

Here's the relevant changelog entry: + Require nonempty alt text for `implicit_figures` (#2844). A figure with an empty caption doesn't make sense. See #2844 for background. If you want to make the image a figure anyway, then add a nonbreaking space as the alt text, or (somewhat hackish and not guaranteed to be future-proof:) add a title beginning with `fig:`. Nathan Sheffield <notifications@github.com> writes:

…

In pandoc 1, images without captions were centered by default. In pandoc 2, images without captions are left-justified. Was this change intended? I did not see documentation of this change in the release notes. I believe this is a bug and images without captions should be centered in pandoc 2. Reproducible example: image.md: ``` # Here's an image:  ``` example_figure.png:  command: `pandoc image.md -o image.pdf Result under pandoc1: [image.pdf](https://github.com/jgm/pandoc/files/1837819/image.pdf) Result under pandoc2: [image-pandoc2.pdf](https://github.com/jgm/pandoc/files/1837820/image-pandoc2.pdf) -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: #4483

[jpeacock29]

Unfortunately, adding a non-breaking space still triggers "Figure 1:" as the caption. Any other suggestions for a work around here? It seems odd that images in pdfs are centered with a caption and left justified without; would you consider a pull request to center all images in pdfs? Thanks!

[trou]

For those having the problem, adding a Zero-width space does the trick.
You can copy the following text (​) and remove the parenthesis.

[nacaru-w]

I wonder if there have been any developments on this. I have tried a thousand ways to do it and still can't make it work.

[jgm]

You could achieve this with a Lua filter:
https://pandoc.org/lua-filters.html#center-images-in-latex-and-html-output

[nacaru-w]

Alright. I finally found a way. I'll leave the answer here for everyone else to see (worked for me in Pandoc 3.1.9):

Using the Lua filter alone will add an unnecessary caption (images with captions are centered by default), so you need to:

1. Create a .lua file (for example, center.lua) that contains the following code:

-- Filter images with this function if the target format is LaTeX.
if FORMAT:match 'latex' then
  function Image (elem)
    -- Surround all images with image-centering raw LaTeX.
    return {
      pandoc.RawInline('latex', '\\hfill\\break{\\centering'),
      elem,
      pandoc.RawInline('latex', '\\par}')
    }
  end
end

2. Remove the implicit_figures plugin when you make the Pandoc call to convert the file, make sure to add the filter to the call:

pandoc --lua-filter=center.lua <YOUR FILE>.md -fmarkdown-implicit_figures -o <OUTPUT FILE>.pdf

Adding a fake caption and then removing the plugin, as some in StackOverflow have suggested, won't work (image sticks to the left).

[jgm]

Instead of -implicit_figures, you could have the Lua filter set the images caption to {}.