alt txt not registered for images in acrobat DC when converting from markdown

[andrew.beet]

I have a markdown document with images defined like below:

![Figure 3.1. Long-term sea surface temperatures ](figures/ex3-1.png "Figure 3.1. Long-term sea surface ")

When this markdown document gets converted to pdf all of the alt text info is not transferred. It gets lost. This is apparent when i perform an accessibility check. 

My doc has 100+ images, it needs to be 508 compliant, and i do not want to enter this text manually.

I see the same issue when converting other formats to pdf

Why does this happen? How can it be remedied? Is this an Adobe issue/bug?

[andrew.beet]

Any adobe developers that can chime in on this?

[Test Screen Name]

Adobe has a huge organisation designed to make quite sure you never hear from an Adobe developer... still, how do you convert this markdown stuff to PDF, exactly? Since surely Acrobat doesn’t do it. 

[andrew.beet]

There are several ways to convert markdown or flavors of markdown to pdf. Pandoc being one of them. And of course, you are right, Adobe doesn't do that it is just interpreting the output. This issue is rooted in the converstion software. However when you convert a bold heading, Adobe understands how to read that and interpret it, because the conversion software has formatted the output in a way that Acrobat can read it

I guess my point/question is rooted in "How does Acrobat interpret alt text?"

When you run the accessability options in acrobat you are told which fields are missing information. So Acrobat clearly has a standard for this. However i don't see any documentation (by Adobe) to suggest how these fields should be formatted.

So how is a developer of conversion software meant to develop when the standards are unknowm?

I am also trying to ask similar questions to the pandoc community

[Test Screen Name]

Acrobat has no fields in the way you have them in your original example. It has a series of invisible objects giving information on the structure and attributes of each visible object. You can't directly code these, it is up to the conversion software to make them.