Hi,
I would like to share this lua filter I made to pass the obsidian image resize workflow to Pandoc.
It should be robust for all(?) cases:
- space and no space between separator and size
- space and no space between width and height
- if only width is passed
Of course options for sizes should be sound
I am not an expert in Lua, so there might be room for improvement. If you see any holes in my code, suggestions and ideas are welcome!
Enjoy 
pandoc.utils = require 'pandoc.utils'
function Image (img)
local size_sep = {} -- Init size table (for width x height)
for i,v in ipairs(img.caption) do -- Loop on the caption table
caption_string = pandoc.utils.stringify(v) -- stringify every table item
if string.find(caption_string, "|") then
index = i
last_word = string.match(caption_string, "(.*)|") -- Last word before | if no space
size = string.match(caption_string, "|(.*)") -- We store the size
if size == '' then -- There is a space between | and size, we look further ahead
for w in string.gmatch(pandoc.utils.stringify(img.caption[index+2]), "([^x]+)") do
table.insert(size_sep, w)
end
if size_sep[2] == nil then -- There might be a space between width and height
size_sep[2] = pandoc.utils.stringify(img.caption[#img.caption])
-- If height is not specified then size_sep[2] = size_sep[1]
end
else -- There is no space, we can split directly
for w in string.gmatch(size, "([^x]+)") do
table.insert(size_sep, w)
end
end
end
end
for i = #img.caption, index, -1 do -- Iterate from end to avoid out of bounds error by successive deletes
img.caption:remove(i) -- Remove all the caption at and after the separator
end
img.caption[index] = pandoc.Str(last_word) -- We put back the last word that have been removed if no space
if size_sep[2] == size_sep[1] then
img.attributes.width = size_sep[1]
else
img.attributes.width = size_sep[1]
img.attributes.height = size_sep[2]
end
return img
end