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": [
"http://mitra/users/admin",
"https://www.w3.org/ns/activitystreams#Public"
],
"id": "http://pasture-one-actor/actor/LpOrqTAeiYM",
"object": {
"type": "Note",
"attributedTo": "http://pasture-one-actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://mitra/users/admin"
],
"id": "http://pasture-one-actor/actor/wI9uznzJK-E",
"published": "2024-03-31T14:30:21Z",
"content": "no description",
"attachment": {
"type": "Document",
"url": "http://pasture-one-actor/images/100.png"
}
}
}
bonfire
{
"canonicalUri": "http://pasture-one-actor/actor/Qua2tz5pUbc",
"date": "2024-03-30T18:02:06.000Z",
"id": "01HT88D89GMX38DHQVSP4E7855",
"objectPostContent": {
"htmlBody": "no description"
},
"verb": {
"verbDisplay": "created"
}
}
mastodon
{
"id": "112186094865530420",
"created_at": "2024-03-30T18:39:16.000Z",
"in_reply_to_id": null,
"in_reply_to_account_id": null,
"sensitive": false,
"spoiler_text": "",
"visibility": "public",
"language": null,
"uri": "http://pasture-one-actor/actor/qaDcdcVgcq4",
"url": "http://pasture-one-actor/actor/qaDcdcVgcq4",
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"edited_at": null,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"content": "no description",
"filtered": [],
"reblog": null,
"account": {
"id": "112186086980725689",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": false,
"bot": false,
"discoverable": false,
"group": false,
"created_at": "2024-03-30T00:00:00.000Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"uri": "http://pasture-one-actor/actor",
"avatar": "http://mastodon/avatars/original/missing.png",
"avatar_static": "http://mastodon/avatars/original/missing.png",
"header": "http://mastodon/headers/original/missing.png",
"header_static": "http://mastodon/headers/original/missing.png",
"followers_count": 0,
"following_count": 0,
"statuses_count": 28,
"last_status_at": "2024-03-30",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "112186094861508052",
"type": "image",
"url": "http://localhost:2970/system/cache/media_attachments/files/112/186/094/861/508/052/original/e1316d9d8f81b6ea.png",
"preview_url": "http://localhost:2970/system/cache/media_attachments/files/112/186/094/861/508/052/small/e1316d9d8f81b6ea.png",
"remote_url": "http://pasture-one-actor/images/100.png",
"preview_remote_url": null,
"text_url": null,
"meta": {
"original": {
"width": 40,
"height": 40,
"size": "40x40",
"aspect": 1.0
},
"small": {
"width": 40,
"height": 40,
"size": "40x40",
"aspect": 1.0
}
},
"description": null,
"blurhash": "U580=SuhfQuhuhfkfQfkfQfQfQfQuhfkfQfk"
}
],
"mentions": [],
"tags": [],
"emojis": [],
"card": null,
"poll": null
}
mitra
{
"id": "018e94eb-23d8-06e0-c2b7-440ab219fb87",
"uri": "http://pasture-one-actor/actor/wI9uznzJK-E",
"url": null,
"created_at": "2024-03-31T14:30:21Z",
"edited_at": null,
"account": {
"id": "018e94e6-9c70-19ea-abbc-25876ee1f927",
"username": "actor",
"acct": "actor@pasture-one-actor",
"actor_id": "http://pasture-one-actor/actor",
"url": "http://pasture-one-actor/actor",
"display_name": "Test Actor",
"created_at": "2024-03-31T14:25:25.104753Z",
"note": "",
"avatar": null,
"header": null,
"locked": false,
"mention_policy": "none",
"bot": false,
"identity_proofs": [],
"payment_options": [],
"fields": [],
"emojis": [],
"followers_count": 0,
"following_count": 0,
"subscribers_count": 0,
"statuses_count": 23,
"source": null,
"role": null,
"authentication_methods": null,
"client_config": null
},
"content": "no description",
"in_reply_to_id": null,
"in_reply_to_account_id": null,
"reblog": null,
"visibility": "public",
"sensitive": false,
"spoiler_text": "",
"pinned": false,
"replies_count": 0,
"favourites_count": 0,
"reblogs_count": 0,
"media_attachments": [
{
"id": "018e94eb-23d4-c6a0-86f6-468ec3158071",
"type": "image",
"url": "http://mitra/media/a6bc63913a8abc9e76e76e4c3fee74ce5221b352937cfc881ad41c2eb50356de.png",
"preview_url": "http://mitra/media/a6bc63913a8abc9e76e76e4c3fee74ce5221b352937cfc881ad41c2eb50356de.png",
"description": null
}
],
"mentions": [
{
"id": "018e94e5-7d86-cd07-c32b-eec115bb657e",
"username": "admin",
"acct": "admin",
"url": "http://mitra/users/admin"
}
],
"tags": [],
"emojis": [],
"favourited": false,
"reblogged": false,
"ipfs_cid": null,
"links": []
}
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": [
"http://mitra/users/admin",
"https://www.w3.org/ns/activitystreams#Public"
],
"id": "http://pasture-one-actor/actor/vRMTTw5NGIc",
"object": {
"type": "Note",
"attributedTo": "http://pasture-one-actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://mitra/users/admin"
],
"id": "http://pasture-one-actor/actor/fmhMll5HgtI",
"published": "2024-03-31T14:30:22Z",
"content": "text",
"attachment": {
"type": "Document",
"url": "http://pasture-one-actor/images/100.png",
"name": "name",
"summary": "summary",
"content": "content"
}
}
}
bonfire
{
"canonicalUri": "http://pasture-one-actor/actor/EZwGAyJQVU8",
"date": "2024-03-30T18:02:11.000Z",
"id": "01HT88DD5RTYDK5XT4KR9RDFRY",
"objectPostContent": {
"htmlBody": "text"
},
"verb": {
"verbDisplay": "created"
}
}
mastodon
{
"id": "112186094926118884",
"created_at": "2024-03-30T18:39:17.000Z",
"in_reply_to_id": null,
"in_reply_to_account_id": null,
"sensitive": false,
"spoiler_text": "",
"visibility": "public",
"language": null,
"uri": "http://pasture-one-actor/actor/TdGga_LMT6Q",
"url": "http://pasture-one-actor/actor/TdGga_LMT6Q",
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"edited_at": null,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"content": "text",
"filtered": [],
"reblog": null,
"account": {
"id": "112186086980725689",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": false,
"bot": false,
"discoverable": false,
"group": false,
"created_at": "2024-03-30T00:00:00.000Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"uri": "http://pasture-one-actor/actor",
"avatar": "http://mastodon/avatars/original/missing.png",
"avatar_static": "http://mastodon/avatars/original/missing.png",
"header": "http://mastodon/headers/original/missing.png",
"header_static": "http://mastodon/headers/original/missing.png",
"followers_count": 0,
"following_count": 0,
"statuses_count": 29,
"last_status_at": "2024-03-30",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "112186094922924125",
"type": "image",
"url": "http://localhost:2970/system/cache/media_attachments/files/112/186/094/922/924/125/original/1b68a9fa90ac9c26.png",
"preview_url": "http://localhost:2970/system/cache/media_attachments/files/112/186/094/922/924/125/small/1b68a9fa90ac9c26.png",
"remote_url": "http://pasture-one-actor/images/100.png",
"preview_remote_url": null,
"text_url": null,
"meta": {
"original": {
"width": 40,
"height": 40,
"size": "40x40",
"aspect": 1.0
},
"small": {
"width": 40,
"height": 40,
"size": "40x40",
"aspect": 1.0
}
},
"description": "summary",
"blurhash": "U7I7%I*0fQ*0*0j[fQj[fQfQfQfQ*0j[fQj["
}
],
"mentions": [],
"tags": [],
"emojis": [],
"card": null,
"poll": null
}
mitra
{
"id": "018e94eb-4aeb-470c-ab7b-94cc3b29c2bf",
"uri": "http://pasture-one-actor/actor/fmhMll5HgtI",
"url": null,
"created_at": "2024-03-31T14:30:22Z",
"edited_at": null,
"account": {
"id": "018e94e6-9c70-19ea-abbc-25876ee1f927",
"username": "actor",
"acct": "actor@pasture-one-actor",
"actor_id": "http://pasture-one-actor/actor",
"url": "http://pasture-one-actor/actor",
"display_name": "Test Actor",
"created_at": "2024-03-31T14:25:25.104753Z",
"note": "",
"avatar": null,
"header": null,
"locked": false,
"mention_policy": "none",
"bot": false,
"identity_proofs": [],
"payment_options": [],
"fields": [],
"emojis": [],
"followers_count": 0,
"following_count": 0,
"subscribers_count": 0,
"statuses_count": 24,
"source": null,
"role": null,
"authentication_methods": null,
"client_config": null
},
"content": "text",
"in_reply_to_id": null,
"in_reply_to_account_id": null,
"reblog": null,
"visibility": "public",
"sensitive": false,
"spoiler_text": "",
"pinned": false,
"replies_count": 0,
"favourites_count": 0,
"reblogs_count": 0,
"media_attachments": [
{
"id": "018e94eb-4ae7-849c-8a7d-2fc8cfafff9e",
"type": "image",
"url": "http://mitra/media/9eae4d25f86e5c6f3fc157fa468e0834e6a3cac4ea45d82658d10898ba8cd8f1.png",
"preview_url": "http://mitra/media/9eae4d25f86e5c6f3fc157fa468e0834e6a3cac4ea45d82658d10898ba8cd8f1.png",
"description": "name"
}
],
"mentions": [
{
"id": "018e94e5-7d86-cd07-c32b-eec115bb657e",
"username": "admin",
"acct": "admin",
"url": "http://mitra/users/admin"
}
],
"tags": [],
"emojis": [],
"favourited": false,
"reblogged": false,
"ipfs_cid": null,
"links": []
}
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": [
"http://mitra/users/admin",
"https://www.w3.org/ns/activitystreams#Public"
],
"id": "http://pasture-one-actor/actor/cATR6iwf8xU",
"object": {
"type": "Note",
"attributedTo": "http://pasture-one-actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://mitra/users/admin"
],
"id": "http://pasture-one-actor/actor/K9igrh5b7j4",
"published": "2024-03-31T14:30:32Z",
"content": "text",
"attachment": [
{
"type": "Document",
"url": "http://pasture-one-actor/assets/FediverseLogo.png",
"name": "name",
"imageType": "image/jpeg"
}
]
}
}
bonfire
{
"canonicalUri": "http://pasture-one-actor/actor/PYntpPRzzlc",
"date": "2024-03-30T18:02:15.000Z",
"id": "01HT88DH2RQTCDS3QTD84Y5HD8",
"objectPostContent": {
"htmlBody": "text"
},
"verb": {
"verbDisplay": "created"
}
}
mastodon
{
"id": "112186095026332763",
"created_at": "2024-03-30T18:39:18.000Z",
"in_reply_to_id": null,
"in_reply_to_account_id": null,
"sensitive": false,
"spoiler_text": "",
"visibility": "public",
"language": null,
"uri": "http://pasture-one-actor/actor/EIomjHMsbVo",
"url": "http://pasture-one-actor/actor/EIomjHMsbVo",
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"edited_at": null,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"content": "text",
"filtered": [],
"reblog": null,
"account": {
"id": "112186086980725689",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": false,
"bot": false,
"discoverable": false,
"group": false,
"created_at": "2024-03-30T00:00:00.000Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"uri": "http://pasture-one-actor/actor",
"avatar": "http://mastodon/avatars/original/missing.png",
"avatar_static": "http://mastodon/avatars/original/missing.png",
"header": "http://mastodon/headers/original/missing.png",
"header_static": "http://mastodon/headers/original/missing.png",
"followers_count": 0,
"following_count": 0,
"statuses_count": 30,
"last_status_at": "2024-03-30",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "112186094999249198",
"type": "image",
"url": "http://localhost:2970/system/cache/media_attachments/files/112/186/094/999/249/198/original/b6ff6d8807ce343e.png",
"preview_url": "http://localhost:2970/system/cache/media_attachments/files/112/186/094/999/249/198/small/b6ff6d8807ce343e.png",
"remote_url": "http://pasture-one-actor/assets/FediverseLogo.png",
"preview_remote_url": null,
"text_url": null,
"meta": {
"original": {
"width": 1548,
"height": 1548,
"size": "1548x1548",
"aspect": 1.0
},
"small": {
"width": 480,
"height": 480,
"size": "480x480",
"aspect": 1.0
}
},
"description": "name",
"blurhash": "UJC$fp*q55T?}fjFEVw[4?K[RT$l9,O?V?X2"
}
],
"mentions": [],
"tags": [],
"emojis": [],
"card": null,
"poll": null
}
mitra
{
"id": "018e94eb-71f3-7c09-b2f1-7ae21a311535",
"uri": "http://pasture-one-actor/actor/K9igrh5b7j4",
"url": null,
"created_at": "2024-03-31T14:30:32Z",
"edited_at": null,
"account": {
"id": "018e94e6-9c70-19ea-abbc-25876ee1f927",
"username": "actor",
"acct": "actor@pasture-one-actor",
"actor_id": "http://pasture-one-actor/actor",
"url": "http://pasture-one-actor/actor",
"display_name": "Test Actor",
"created_at": "2024-03-31T14:25:25.104753Z",
"note": "",
"avatar": null,
"header": null,
"locked": false,
"mention_policy": "none",
"bot": false,
"identity_proofs": [],
"payment_options": [],
"fields": [],
"emojis": [],
"followers_count": 0,
"following_count": 0,
"subscribers_count": 0,
"statuses_count": 25,
"source": null,
"role": null,
"authentication_methods": null,
"client_config": null
},
"content": "text",
"in_reply_to_id": null,
"in_reply_to_account_id": null,
"reblog": null,
"visibility": "public",
"sensitive": false,
"spoiler_text": "",
"pinned": false,
"replies_count": 0,
"favourites_count": 0,
"reblogs_count": 0,
"media_attachments": [
{
"id": "018e94eb-71f0-0b4d-c7d5-ca675df82d09",
"type": "image",
"url": "http://mitra/media/2d7a61d31393a44edf2a30160cdd70b3582a4f97d5b550f8141dfee1641b4ae7.png",
"preview_url": "http://mitra/media/2d7a61d31393a44edf2a30160cdd70b3582a4f97d5b550f8141dfee1641b4ae7.png",
"description": "name"
}
],
"mentions": [
{
"id": "018e94e5-7d86-cd07-c32b-eec115bb657e",
"username": "admin",
"acct": "admin",
"url": "http://mitra/users/admin"
}
],
"tags": [],
"emojis": [],
"favourited": false,
"reblogged": false,
"ipfs_cid": null,
"links": []
}
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": [
"http://mitra/users/admin",
"https://www.w3.org/ns/activitystreams#Public"
],
"id": "http://pasture-one-actor/actor/y_xvNxYW9Bw",
"object": {
"type": "Note",
"attributedTo": "http://pasture-one-actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://mitra/users/admin"
],
"id": "http://pasture-one-actor/actor/B69SviffAzk",
"published": "2024-03-31T14:30:42Z",
"content": "no comment in attachment",
"attachment": [
{
"type": "Document",
"url": "http://pasture-one-actor/assets/FediverseLogo.png"
}
]
}
}
bonfire
{
"canonicalUri": "http://pasture-one-actor/actor/x5uE71Zmlfg",
"date": "2024-03-30T18:02:19.000Z",
"id": "01HT88DMZRMPPW3B61ERVHSW59",
"objectPostContent": {
"htmlBody": "no comment in attachment"
},
"verb": {
"verbDisplay": "created"
}
}
mastodon
{
"id": "112186095093438264",
"created_at": "2024-03-30T18:39:20.000Z",
"in_reply_to_id": null,
"in_reply_to_account_id": null,
"sensitive": false,
"spoiler_text": "",
"visibility": "public",
"language": null,
"uri": "http://pasture-one-actor/actor/WruaPw_Bwuc",
"url": "http://pasture-one-actor/actor/WruaPw_Bwuc",
"replies_count": 0,
"reblogs_count": 0,
"favourites_count": 0,
"edited_at": null,
"favourited": false,
"reblogged": false,
"muted": false,
"bookmarked": false,
"content": "no comment in attachment",
"filtered": [],
"reblog": null,
"account": {
"id": "112186086980725689",
"username": "actor",
"acct": "actor@pasture-one-actor",
"display_name": "Test Actor",
"locked": false,
"bot": false,
"discoverable": false,
"group": false,
"created_at": "2024-03-30T00:00:00.000Z",
"note": "",
"url": "http://pasture-one-actor/actor",
"uri": "http://pasture-one-actor/actor",
"avatar": "http://mastodon/avatars/original/missing.png",
"avatar_static": "http://mastodon/avatars/original/missing.png",
"header": "http://mastodon/headers/original/missing.png",
"header_static": "http://mastodon/headers/original/missing.png",
"followers_count": 0,
"following_count": 0,
"statuses_count": 31,
"last_status_at": "2024-03-30",
"emojis": [],
"fields": []
},
"media_attachments": [
{
"id": "112186095069349828",
"type": "image",
"url": "http://localhost:2970/system/cache/media_attachments/files/112/186/095/069/349/828/original/3455265219d3f2b9.png",
"preview_url": "http://localhost:2970/system/cache/media_attachments/files/112/186/095/069/349/828/small/3455265219d3f2b9.png",
"remote_url": "http://pasture-one-actor/assets/FediverseLogo.png",
"preview_remote_url": null,
"text_url": null,
"meta": {
"original": {
"width": 1548,
"height": 1548,
"size": "1548x1548",
"aspect": 1.0
},
"small": {
"width": 480,
"height": 480,
"size": "480x480",
"aspect": 1.0
}
},
"description": null,
"blurhash": "UJC$fp*q55T?}fjFEVw[4?K[RT$l9,O?V?X2"
}
],
"mentions": [],
"tags": [],
"emojis": [],
"card": null,
"poll": null
}
mitra
{
"id": "018e94eb-9909-753b-ce1e-8b139f4e7b9c",
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