Image Description¶
The Image type is defined in ActivityStreams Vocabulary.
In this support table, we only consider how the image description, commonly called AltText is handled. Image descriptions are important from an accessibility standpoint, see WCAG 2.2. Text Alternatives.
It seems that certain implementations, e.g. firefish, store the image description on a per image URL basis and not for every instance of an image reference.
Examples¶
Example 1¶
activity
{
"@context": [
"https://www.w3.org/ns/activitystreams",
{
"Hashtag": "as:Hashtag",
"sensitive": "as:sensitive"
}
],
"type": "Create",
"actor": "http://pasture-one-actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://hollo/@john"
],
"id": "http://pasture-one-actor/actor/gZTNqNW48zA",
"published": "2024-11-03T15:01:24Z",
"object": {
"type": "Note",
"attributedTo": "http://pasture-one-actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://hollo/@john"
],
"id": "http://pasture-one-actor/actor/k749WOc8GIM",
"published": "2024-11-03T15:01:24Z",
"content": "no description",
"attachment": {
"type": "Document",
"url": "http://pasture-one-actor/images/100.png"
},
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
cattle_grid
{
"field_context": [
"https://www.w3.org/ns/activitystreams",
{
"Hashtag": "as:Hashtag",
"sensitive": "as:sensitive"
}
],
"id": "http://pasture-one-actor/actor/3LGiSIRzGGQ",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://cattle_grid/actor/0tVne6n_zxpVEnZifwQ-1Q"
],
"published": "2024-11-02T20:49:57Z",
"type": "Create",
"actor": "http://pasture-one-actor/actor",
"object": {
"id": "http://pasture-one-actor/actor/m8kq4V7ht4Q",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://cattle_grid/actor/0tVne6n_zxpVEnZifwQ-1Q"
],
"published": "2024-11-02T20:49:57Z",
"type": "Note",
"attributedTo": "http://pasture-one-actor/actor",
"content": "no description",
"attachment": [
{
"type": "Document",
"url": "http://pasture-one-actor/images/100.png"
}
]
}
}
hollo
{
"id": "0192f28b-89a0-7426-b49d-6d8a4aa4da90",
"created_at": "2024-11-03T15:01:24.000Z",
"in_reply_to_id": null,
"sensitive": false,
"spoiler_text": "",
"visibility": "public",
"language": null,
"uri": "http://pasture-one-actor/actor/k749WOc8GIM",
"url": null,
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"pinned": false,
"content": "no description",
"reblog": null,
"quote_id": null,
"quote": null,
"application": null,
"account": {
"id": "0192f28a-d788-75f0-8926-0221de3ee90c",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": false,
"bot": false,
"created_at": "2024-11-03T15:00:38.344Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://hollo/image/avatars/original/missing.png",
"avatar_static": "http://hollo/image/avatars/original/missing.png",
"header": "http://hollo/image/headers/original/missing.png",
"header_static": "http://hollo/image/headers/original/missing.png",
"followers_count": 0,
"following_count": 0,
"statuses_count": 0,
"moved": null,
"last_status_at": null,
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "0192f28b-8b52-7f51-b4ba-18dd0f84766d",
"type": "image",
"url": "http://pasture-one-actor/images/100.png",
"preview_url": "http://pasture-one-actor/images/100.png",
"remote_url": null,
"text_url": null,
"meta": {
"original": {
"width": 512,
"height": 512,
"size": "512x512",
"aspect": 1
},
"small": {
"width": 512,
"height": 512,
"size": "512x512",
"aspect": 1
},
"focus": {
"x": 0,
"y": 0
}
},
"description": null,
"blurhash": null
}
],
"mentions": [],
"tags": [],
"card": null,
"emojis": [],
"emoji_reactions": [],
"poll": null,
"filtered": null
}
Example 2¶
activity
{
"@context": [
"https://www.w3.org/ns/activitystreams",
{
"Hashtag": "as:Hashtag",
"sensitive": "as:sensitive"
}
],
"type": "Create",
"actor": "http://pasture-one-actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://hollo/@john"
],
"id": "http://pasture-one-actor/actor/3hvqk0jlIjU",
"published": "2024-11-03T15:01:24Z",
"object": {
"type": "Note",
"attributedTo": "http://pasture-one-actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://hollo/@john"
],
"id": "http://pasture-one-actor/actor/XktYYGWCgWI",
"published": "2024-11-03T15:01:24Z",
"content": "text",
"attachment": {
"type": "Document",
"url": "http://pasture-one-actor/images/100.png",
"name": "name",
"summary": "summary",
"content": "content"
},
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
cattle_grid
{
"field_context": [
"https://www.w3.org/ns/activitystreams",
{
"Hashtag": "as:Hashtag",
"sensitive": "as:sensitive"
}
],
"id": "http://pasture-one-actor/actor/dSJXKGXzV3E",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://cattle_grid/actor/0tVne6n_zxpVEnZifwQ-1Q"
],
"published": "2024-11-02T20:49:57Z",
"type": "Create",
"actor": "http://pasture-one-actor/actor",
"object": {
"id": "http://pasture-one-actor/actor/xI0fRdbVmto",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://cattle_grid/actor/0tVne6n_zxpVEnZifwQ-1Q"
],
"published": "2024-11-02T20:49:57Z",
"type": "Note",
"attributedTo": "http://pasture-one-actor/actor",
"content": "text",
"attachment": [
{
"type": "Document",
"url": "http://pasture-one-actor/images/100.png",
"name": "name",
"summary": "summary",
"content": "content"
}
]
}
}
hollo
{
"id": "0192f28b-89a0-7426-b49d-6d8acd2a76a9",
"created_at": "2024-11-03T15:01:24.000Z",
"in_reply_to_id": null,
"sensitive": false,
"spoiler_text": "",
"visibility": "public",
"language": null,
"uri": "http://pasture-one-actor/actor/XktYYGWCgWI",
"url": null,
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"pinned": false,
"content": "text",
"reblog": null,
"quote_id": null,
"quote": null,
"application": null,
"account": {
"id": "0192f28a-d788-75f0-8926-0221de3ee90c",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": false,
"bot": false,
"created_at": "2024-11-03T15:00:38.344Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://hollo/image/avatars/original/missing.png",
"avatar_static": "http://hollo/image/avatars/original/missing.png",
"header": "http://hollo/image/headers/original/missing.png",
"header_static": "http://hollo/image/headers/original/missing.png",
"followers_count": 0,
"following_count": 0,
"statuses_count": 0,
"moved": null,
"last_status_at": null,
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "0192f28b-8e67-7e2d-b6cf-a7aec0365730",
"type": "image",
"url": "http://pasture-one-actor/images/100.png",
"preview_url": "http://pasture-one-actor/images/100.png",
"remote_url": null,
"text_url": null,
"meta": {
"original": {
"width": 512,
"height": 512,
"size": "512x512",
"aspect": 1
},
"small": {
"width": 512,
"height": 512,
"size": "512x512",
"aspect": 1
},
"focus": {
"x": 0,
"y": 0
}
},
"description": "summary",
"blurhash": null
}
],
"mentions": [],
"tags": [],
"card": null,
"emojis": [],
"emoji_reactions": [],
"poll": null,
"filtered": null
}
Example 3¶
activity
{
"@context": [
"https://www.w3.org/ns/activitystreams",
{
"Hashtag": "as:Hashtag",
"sensitive": "as:sensitive"
}
],
"type": "Create",
"actor": "http://pasture-one-actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://hollo/@john"
],
"id": "http://pasture-one-actor/actor/PstC-yPyS1U",
"published": "2024-11-03T15:01:25Z",
"object": {
"type": "Note",
"attributedTo": "http://pasture-one-actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://hollo/@john"
],
"id": "http://pasture-one-actor/actor/N-8ikeAQ7Fg",
"published": "2024-11-03T15:01:25Z",
"content": "text",
"attachment": [
{
"type": "Document",
"url": "http://pasture-one-actor/assets/FediverseLogo.png",
"name": "name",
"imageType": "image/jpeg"
}
],
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
cattle_grid
{
"field_context": [
"https://www.w3.org/ns/activitystreams",
{
"Hashtag": "as:Hashtag",
"sensitive": "as:sensitive"
}
],
"id": "http://pasture-one-actor/actor/_C3fGlFAeg0",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://cattle_grid/actor/0tVne6n_zxpVEnZifwQ-1Q"
],
"published": "2024-11-02T20:49:58Z",
"type": "Create",
"actor": "http://pasture-one-actor/actor",
"object": {
"id": "http://pasture-one-actor/actor/icVzxUE8h-g",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://cattle_grid/actor/0tVne6n_zxpVEnZifwQ-1Q"
],
"published": "2024-11-02T20:49:58Z",
"type": "Note",
"attributedTo": "http://pasture-one-actor/actor",
"content": "text",
"attachment": [
{
"type": "Document",
"url": "http://pasture-one-actor/assets/FediverseLogo.png",
"name": "name",
"imageType": "image/jpeg"
}
]
}
}
hollo
{
"id": "0192f28b-8d88-793a-a2cf-600c4a2707fd",
"created_at": "2024-11-03T15:01:25.000Z",
"in_reply_to_id": null,
"sensitive": false,
"spoiler_text": "",
"visibility": "public",
"language": null,
"uri": "http://pasture-one-actor/actor/N-8ikeAQ7Fg",
"url": null,
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"pinned": false,
"content": "text",
"reblog": null,
"quote_id": null,
"quote": null,
"application": null,
"account": {
"id": "0192f28a-d788-75f0-8926-0221de3ee90c",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": false,
"bot": false,
"created_at": "2024-11-03T15:00:38.344Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://hollo/image/avatars/original/missing.png",
"avatar_static": "http://hollo/image/avatars/original/missing.png",
"header": "http://hollo/image/headers/original/missing.png",
"header_static": "http://hollo/image/headers/original/missing.png",
"followers_count": 0,
"following_count": 0,
"statuses_count": 0,
"moved": null,
"last_status_at": null,
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "0192f28b-91e0-73bc-a2d7-9964917f0da7",
"type": "image",
"url": "http://pasture-one-actor/assets/FediverseLogo.png",
"preview_url": "http://pasture-one-actor/assets/FediverseLogo.png",
"remote_url": null,
"text_url": null,
"meta": {
"original": {
"width": 512,
"height": 512,
"size": "512x512",
"aspect": 1
},
"small": {
"width": 512,
"height": 512,
"size": "512x512",
"aspect": 1
},
"focus": {
"x": 0,
"y": 0
}
},
"description": "name",
"blurhash": null
}
],
"mentions": [],
"tags": [],
"card": null,
"emojis": [],
"emoji_reactions": [],
"poll": null,
"filtered": null
}
Example 4¶
activity
{
"@context": [
"https://www.w3.org/ns/activitystreams",
{
"Hashtag": "as:Hashtag",
"sensitive": "as:sensitive"
}
],
"type": "Create",
"actor": "http://pasture-one-actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://hollo/@john"
],
"id": "http://pasture-one-actor/actor/tmquwCU7PyA",
"published": "2024-11-03T15:01:26Z",
"object": {
"type": "Note",
"attributedTo": "http://pasture-one-actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://hollo/@john"
],
"id": "http://pasture-one-actor/actor/vEOfoyjDUE4",
"published": "2024-11-03T15:01:26Z",
"content": "no comment in attachment",
"attachment": [
{
"type": "Document",
"url": "http://pasture-one-actor/assets/FediverseLogo.png"
}
],
"tag": [
{
"type": "Mention",
"href": "http://gotosocial/users/cookie"
}
]
}
}
cattle_grid
{
"field_context": [
"https://www.w3.org/ns/activitystreams",
{
"Hashtag": "as:Hashtag",
"sensitive": "as:sensitive"
}
],
"id": "http://pasture-one-actor/actor/E824RBS3Pfs",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://cattle_grid/actor/0tVne6n_zxpVEnZifwQ-1Q"
],
"published": "2024-11-02T20:49:59Z",
"type": "Create",
"actor": "http://pasture-one-actor/actor",
"object": {
"id": "http://pasture-one-actor/actor/5uo2lh8Aafo",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://cattle_grid/actor/0tVne6n_zxpVEnZifwQ-1Q"
],
"published": "2024-11-02T20:49:59Z",
"type": "Note",
"attributedTo": "http://pasture-one-actor/actor",
"content": "no comment in attachment",
"attachment": [
{
"type": "Document",
"url": "http://pasture-one-actor/assets/FediverseLogo.png"
}
]
}
}
hollo
{
"id": "0192f28b-9170-7c32-9ed8-c8a0694af2b3",
"created_at": "2024-11-03T15:01:26.000Z",
"in_reply_to_id": null,
"sensitive": false,
"spoiler_text": "",
"visibility": "public",
"language": null,
"uri": "http://pasture-one-actor/actor/vEOfoyjDUE4",
"url": null,
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"pinned": false,
"content": "no comment in attachment",
"reblog": null,
"quote_id": null,
"quote": null,
"application": null,
"account": {
"id": "0192f28a-d788-75f0-8926-0221de3ee90c",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": false,
"bot": false,
"created_at": "2024-11-03T15:00:38.344Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"avatar": "http://hollo/image/avatars/original/missing.png",
"avatar_static": "http://hollo/image/avatars/original/missing.png",
"header": "http://hollo/image/headers/original/missing.png",
"header_static": "http://hollo/image/headers/original/missing.png",
"followers_count": 0,
"following_count": 0,
"statuses_count": 0,
"moved": null,
"last_status_at": null,
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "0192f28b-94c8-7947-85b4-0f7672363752",
"type": "image",
"url": "http://pasture-one-actor/assets/FediverseLogo.png",
"preview_url": "http://pasture-one-actor/assets/FediverseLogo.png",
"remote_url": null,
"text_url": null,
"meta": {
"original": {
"width": 512,
"height": 512,
"size": "512x512",
"aspect": 1
},
"small": {
"width": 512,
"height": 512,
"size": "512x512",
"aspect": 1
},
"focus": {
"x": 0,
"y": 0
}
},
"description": null,
"blurhash": null
}
],
"mentions": [],
"tags": [],
"card": null,
"emojis": [],
"emoji_reactions": [],
"poll": null,
"filtered": null
}