Caveats: I am writing this primarily for translators who do not use Adobe InDesign, but have customers that do. I write as a translator who has often found this sort of project challenging; also as one who has no first-hand knowledge of Adobe InDesign or any other desktop layout software. If, as a result, my explanations need correction or refinement, please feel free to comment accordingly. I further write as a translator who has no first-hand knowledge of any of the TenTs mentioned here (sorry if that comes as a surprise ...), so, again, if my explanations need correction or refinement, please feel free to comment accordingly.
Note that this is not a type of project that I have encountered personally.
For more on TenTs, see Jost Zetzsche's Tool Box Journal (basic subscription is free), or The Translator's Tool Box: A Computer Primer for Translators Version 12.
Kilgray’s Language Terminal has changed the way translators can work with InDesign files. One of the various features of Language Terminal is the ability to upload InDesign IDML files of any version to a server, which converts these files to a memoQ-specific version of XLIFF.
Kilgray’s Language Terminal also supports Adobe InDesign INDD files (which are otherwise not readable by anything other than InDesign). It does this by converting them to IDML behind the scenes thereby allowing translators to download a PDF preview of an INDD + MQXLZ package for translation in memoQ. This package can be analysed by any ZIP archiver in order to extract the XLIFF file and translate using any other another TenT tool. By uploading the MQXLZ file back into Language Terminal, one can then download the translated IDML.
Also, Memsource Cloud now integrates with products by several new technology partners including Frontlab offering similar capabilities: besides IDML, one can upload INDD to Memsource Cloud (which will be converted to IDML behind the scenes), translate it and download the translated IDML file.This workflow works better if the layout team is familiar with translators' needs and more particularly if they prepare the layout specifically for translation. One of many possible links on this is called:
8 Steps to Optimize InDesign Files for Translation.
Note that lots can go wrong, so time must be allowed for corrective work by the layout team.
As 8 Steps to Optimize InDesign Files for Translation says under the subheading Intelligent use of white space in InDesign document layout:
The biggest challenge in designing InDesign document templates for multilingual projects is creating page layout that will accommodate post-translation text expansion. It is not easy to create a source English document that has enough of white space or "breathing room" around text elements. Many languages (e.g. Russian, German, Italian, Latin American Spanish) can expand the line count by as much as 35%.
Language expansion is further magnified by narrow containers, e.g. side notes in the margin, table cells, indented text or boxed cautions and warnings. In addition, some eastern languages (e.g. Arabic, Farsi, Urdu) display text "right-to-left"; this requires right alignment and right-to-left layout modification. Text expansion and text direction require a flexible layout designed by professionals who understand the challenges of multilingual desktop publishing and graphic localization. Your translation company can be a great help in this regard.In the case of French to English, and many other language pairs, the problem is not so much language expansion, but language contraction.