[WR/ARIB] Compatibility with ARIB-TTML / 1. Image handling

[himorin]

Per: w3c/ttwg#116
Comment 3 (#545), 1

ARIB-TTML can render the images with the texts in the same TTML document. A BASE64 encoded image can be embedded into the document by ‘smpte:image’ element. Such an embedded image or an image referenced as the external entity can be rendered by ‘smpte:backgroundImage’ attribute.

[nigelmegitt]

I am interested to know more about the use case for this. For example, perhaps it is used to allow non-Unicode symbols such as company logos to be included, or perhaps it is used to provide complex background images behind the text, with graphical effects like gradients, bevels etc.

[css-meeting-bot]

The Timed Text Working Group just discussed [WR/ARIB] Compatibility with ARIB-TTML / 1. Image handling imsc#546, and agreed to the following:

• SUMMARY: TTWG would like to know more about the use cases for this feature, and complexity of implementation.

The full IRC log of that discussion

<nigel> Topic: [WR/ARIB] Compatibility with ARIB-TTML / 1. Image handling imsc#546
<nigel> github: https://github.com//issues/546
<nigel> Nigel: I want to know more about the use case for this.
<nigel> Pierre: I agree this is the essential question.
<nigel> .. Thinking about going back to ARIB, asking for sample documents or exemplar renders
<nigel> .. would be really helpful.
<nigel> Cyril: I remember that when we discussed mixing text and image profile we said we would
<nigel> .. not do it because there are other ways to do it, and that there's a complexity side to it too.
<nigel> Pierre: That's my recollection too. My question is do they have use cases that cannot be
<nigel> .. solved with the current approach.
<nigel> .. Image and Text can mean many different things. It would be good to understand what they mean.
<nigel> Cyril: I wonder if we should ask about the complexity of implementation too.
<nigel> Pierre: Yes I think that would be great if they could point to a reference implementation so
<nigel> .. we can understand complexity.
<nigel> Nigel: Two things for me to add to the list for w3c/ttwg#116: 1. Request more info about use cases; 2. Ask about complexity.
<nigel> SUMMARY: TTWG would like to know more about the use cases for this feature, and complexity of implementation.

[mikedo]

Some of you may recall I was the one concerned about addressing Japanese captioning needs for small glyph-like images. It may be faster/easier to ask an individual familiar with it. I'll reach out.

[nigelmegitt]

@mikedo I'm preparing a response to ARIB and wonder if you have received any response from your contacts that we should take into account?

[nigelmegitt]

@mikedo sorry, I just noticed #547 (comment) - is that the answer to the same question?

[nigelmegitt]

@mikedo posted https://lists.w3.org/Archives/Public/public-tt/2020Jul/0018.html in response to the image question, quoted here for convenience since it is public anyway:

There are two ways using image in TTML in Japan.

One is using SVG image format to define another Kanji that is not
defined ARIB STD-B62. In fact, there are many Kanji that is not
in the standard Japanese fontset, expressing persons name and/or
locations. Also some TV programs in Japan, Broadcaster uses emoji character
using SVG.

Another usecase of image, the broadcasters can transmit
PNG image on TTML, this TTML is not for captioning the programs,
but for alerting with messages. We call it "superimpose".
For example, if there is an earthquake and tsunami coming up to,
broadcaster send warning message in TTML format.
In this case, they might add a map where will be serious.