tex4ebook and \coverimage[someOptions]{AbsolutePath/someimage.jpg} does not work

Question

I use tex4ebook with \coverimage[someOptions]{AbsolutePath/someimage.jpg} in the document, directly after \begin{document}. But the AbsolutePath is not respected and does not find someimage.jpg, respectively is not shown in the epub.

As AbsolutePath I use something like C:/Somepath/folder/anotherfolder/someimage.jpg. But in the epub no image is shown.

When I use someimage.jpg located in the current folder, where the .tex file is, it works and the someimage.jpg is shown in the epub.

Only the absolute path is not showing the image in the epub. But of cource the someimage.jpg is located in the AbsolutePath folder.

Is there anything to know that I miss?

It seems as if the

\graphicpath{{PathA/}{PathB/}{C:/folder/anotherfolder/}}

does not work with tex4ebook. Though it was said, that all options with \includegraphics[]{} will work with \coverimage[]{}.

Is there a fix to it?

Answer 1

tex4ebook doesn't copy images, you need to do it using a build file. I've handled a similar case some time ago in this answer, but it doesn't work correctly with tex4ebook. Here is a fixed version, which also contains other DOM filter that you want to use:

local mkutils = require "mkutils"
local domfilter = require "make4ht-domfilter"

local allowed_chars = {
  ["-"] = true,
  ["."] = true
}
local function fix_colons(id)
  -- match every non alphanum character
  return id:gsub("[%W]", function(s)
    -- some characters are allowed, we don't need to replace them
    if allowed_chars[s] then return s end
    -- in other cases, replace with underscore
    return "_"
  end)
end

local function id_colons(obj)
  -- replace : characters in links and ids with unserscores
  obj:traverse_elements(function(el) 
    local name = string.lower(obj:get_element_name(el))
    if name == "a" then
      local href = el:get_attribute("href")
      -- don't replace colons in external links
      if href and not href:match("[a-z]%://") then
        local base, id = href:match("(.*)%#(.*)")
        if base and id then
          id = fix_colons(id)
          el:set_attribute("href", base .. "#" .. id)
        end
      end
    end
    local id  = el:get_attribute("id")
    if id then
      el:set_attribute("id", fix_colons(id))
    end
  end)
  return obj
end

local function fix_img_names(dom)
    for _, img in ipairs(dom:query_selector("img")) do
        local src = img:get_attribute("src")
        if src then
            -- remove path specification
            src = src:match("([^/]+)$")
            img:set_attribute("src", src)
        end
    end
    return dom
end

local process = domfilter {id_colons,fix_img_names}


local function image_copy(path, parameters)
  -- get image basename
  local basename = path:match("([^/]+)$")
  -- if outdir is empty, keep it empty, otherwise add / separator
  local outdir = parameters.outdir == "" and "" or parameters.outdir .. "/"
  -- handle trailing //
  outdir = outdir:gsub("//$","/")
  local output_file = outdir .. basename
  for pos, name in pairs(Make.lgfile.files) do 
    if name == path then
      Make.lgfile.files[pos] = output_file
    end
  end
  mkutils.cp(path, output_file)
end

Make:match("png$", function(path, parameters)
  image_copy(path, parameters)
  -- prevent further processing of the image
  return false
end)

Make:match("jpg$", function(path, parameters)
  image_copy(path, parameters)
  -- prevent further processing of the image
  return false
end)


if mode=="draft" then
  Make:htlatex {}
else
  Make:htlatex {}
  Make:xindy {modules={"duden-utf8"}}
  Make:biber {}
  Make:htlatex {}
  Make:htlatex {}
end



Make:match("html$", process)

Details on how it works are in the link above.