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¶
```json title="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://misskey/users/9q9s1mag5omu0001"
],
"id": "http://pasture_one_actor/actor/WITxP9FeVGc",
"object": {
"type": "Note",
"attributedTo": "http://pasture_one_actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://misskey/users/9q9s1mag5omu0001"
],
"id": "http://pasture_one_actor/actor/xsQOemiWuLY",
"published": "2024-02-28T19:54:11Z",
"content": "no description",
"attachment": {
"type": "Document",
"url": "http://pasture_one_actor/images/100.png"
}
}
}
```
```json title="misskey"
{
"id": "9q9s4gxkba8v000q",
"createdAt": "2024-02-28T19:54:11.000Z",
"userId": "9q9s36raba8v0002",
"user": {
"id": "9q9s36raba8v0002",
"name": "Test Actor",
"username": "actor",
"host": "pasture_one_actor",
"avatarUrl": "http://misskey/identicon/actor@pasture_one_actor",
"avatarBlurhash": null,
"avatarDecorations": [],
"isBot": false,
"isCat": false,
"instance": {
"name": null,
"softwareName": null,
"softwareVersion": null,
"iconUrl": null,
"faviconUrl": null,
"themeColor": null
},
"emojis": {},
"onlineStatus": "unknown"
},
"text": "no description",
"cw": null,
"visibility": "public",
"localOnly": false,
"reactionAcceptance": null,
"renoteCount": 0,
"repliesCount": 0,
"reactions": {},
"reactionEmojis": {},
"emojis": {},
"fileIds": [
"9q9s4hebba8v000p"
],
"files": [
{
"id": "9q9s4hebba8v000p",
"createdAt": "2024-02-28T19:54:11.603Z",
"name": "100.png",
"type": "image/png",
"md5": "4b09917dc25213231a21fb3480f9c608",
"size": 0,
"isSensitive": false,
"blurhash": "e09%U}-nfQ-nfQ-nj@fQj@fQfQfQfQfQfQ-nj@fQj@fQfQfQfQfQfQ",
"properties": {
"width": 40,
"height": 40
},
"url": "http://pasture_one_actor/images/100.png",
"thumbnailUrl": "http://pasture_one_actor/images/100.png",
"comment": null,
"folderId": null,
"folder": null,
"userId": null,
"user": null
}
],
"replyId": null,
"renoteId": null,
"uri": "http://pasture_one_actor/actor/xsQOemiWuLY",
"clippedCount": 0
}
```
Example 2¶
```json title="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://misskey/users/9q9s1mag5omu0001"
],
"id": "http://pasture_one_actor/actor/abWqJz52XCM",
"object": {
"type": "Note",
"attributedTo": "http://pasture_one_actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://misskey/users/9q9s1mag5omu0001"
],
"id": "http://pasture_one_actor/actor/aO2rCgkkR1E",
"published": "2024-02-28T19:54:13Z",
"content": "text",
"attachment": {
"type": "Document",
"url": "http://pasture_one_actor/images/100.png",
"name": "name",
"summary": "summary",
"content": "content"
}
}
}
```
```json title="misskey"
{
"id": "9q9s4ih4ba8v000s",
"createdAt": "2024-02-28T19:54:13.000Z",
"userId": "9q9s36raba8v0002",
"user": {
"id": "9q9s36raba8v0002",
"name": "Test Actor",
"username": "actor",
"host": "pasture_one_actor",
"avatarUrl": "http://misskey/identicon/actor@pasture_one_actor",
"avatarBlurhash": null,
"avatarDecorations": [],
"isBot": false,
"isCat": false,
"instance": {
"name": null,
"softwareName": null,
"softwareVersion": null,
"iconUrl": null,
"faviconUrl": null,
"themeColor": null
},
"emojis": {},
"onlineStatus": "unknown"
},
"text": "text",
"cw": null,
"visibility": "public",
"localOnly": false,
"reactionAcceptance": null,
"renoteCount": 0,
"repliesCount": 0,
"reactions": {},
"reactionEmojis": {},
"emojis": {},
"fileIds": [
"9q9s4iyuba8v000r"
],
"files": [
{
"id": "9q9s4iyuba8v000r",
"createdAt": "2024-02-28T19:54:13.638Z",
"name": "100.png",
"type": "image/png",
"md5": "ba80bac22a0685b94fe67a66cae7a323",
"size": 0,
"isSensitive": false,
"blurhash": "e3Pxv:}VfQ}VfQ}VjtfQjtfQfQfQfQfQfQ}VjtfQjtfQfQfQfQfQfQ",
"properties": {
"width": 40,
"height": 40
},
"url": "http://pasture_one_actor/images/100.png",
"thumbnailUrl": "http://pasture_one_actor/images/100.png",
"comment": "name",
"folderId": null,
"folder": null,
"userId": null,
"user": null
}
],
"replyId": null,
"renoteId": null,
"uri": "http://pasture_one_actor/actor/aO2rCgkkR1E",
"clippedCount": 0
}
```
Example 3¶
```json title="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://misskey/users/9q9s1mag5omu0001"
],
"id": "http://pasture_one_actor/actor/U5wzea-uDJM",
"object": {
"type": "Note",
"attributedTo": "http://pasture_one_actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://misskey/users/9q9s1mag5omu0001"
],
"id": "http://pasture_one_actor/actor/azNlD0-qW30",
"published": "2024-02-28T19:54:15Z",
"content": "text",
"attachment": [
{
"type": "Document",
"url": "http://pasture_one_actor/assets/FediverseLogo.png",
"name": "name",
"imageType": "image/jpeg"
}
]
}
}
```
```json title="misskey"
{
"id": "9q9s4k0oba8v000u",
"createdAt": "2024-02-28T19:54:15.000Z",
"userId": "9q9s36raba8v0002",
"user": {
"id": "9q9s36raba8v0002",
"name": "Test Actor",
"username": "actor",
"host": "pasture_one_actor",
"avatarUrl": "http://misskey/identicon/actor@pasture_one_actor",
"avatarBlurhash": null,
"avatarDecorations": [],
"isBot": false,
"isCat": false,
"instance": {
"name": null,
"softwareName": null,
"softwareVersion": null,
"iconUrl": null,
"faviconUrl": null,
"themeColor": null
},
"emojis": {},
"onlineStatus": "unknown"
},
"text": "text",
"cw": null,
"visibility": "public",
"localOnly": false,
"reactionAcceptance": null,
"renoteCount": 0,
"repliesCount": 0,
"reactions": {},
"reactionEmojis": {},
"emojis": {},
"fileIds": [
"9q9s4kmiba8v000t"
],
"files": [
{
"id": "9q9s4kmiba8v000t",
"createdAt": "2024-02-28T19:54:15.786Z",
"name": "FediverseLogo.png",
"type": "image/png",
"md5": "85e7feae66363e9e200570a28b0cf20a",
"size": 0,
"isSensitive": false,
"blurhash": "eQF5X3.}4.YJIm}ynOEUxBt89IK[N1xI-T9,TJRPX3$#ASNFo}aPtP",
"properties": {
"width": 1548,
"height": 1548
},
"url": "http://pasture_one_actor/assets/FediverseLogo.png",
"thumbnailUrl": "http://pasture_one_actor/assets/FediverseLogo.png",
"comment": "name",
"folderId": null,
"folder": null,
"userId": null,
"user": null
}
],
"replyId": null,
"renoteId": null,
"uri": "http://pasture_one_actor/actor/azNlD0-qW30",
"clippedCount": 0
}
```
Example 4¶
```json title="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://misskey/users/9q9s1mag5omu0001"
],
"id": "http://pasture_one_actor/actor/uRu9T5VE3XQ",
"object": {
"type": "Note",
"attributedTo": "http://pasture_one_actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://misskey/users/9q9s1mag5omu0001"
],
"id": "http://pasture_one_actor/actor/93ekpgPNG-w",
"published": "2024-02-28T19:54:17Z",
"content": "no comment in attachment",
"attachment": [
{
"type": "Document",
"url": "http://pasture_one_actor/assets/FediverseLogo.png"
}
]
}
}
```
```json title="misskey"
{
"id": "9q9s4lk8ba8v000v",
"createdAt": "2024-02-28T19:54:17.000Z",
"userId": "9q9s36raba8v0002",
"user": {
"id": "9q9s36raba8v0002",
"name": "Test Actor",
"username": "actor",
"host": "pasture_one_actor",
"avatarUrl": "http://misskey/identicon/actor@pasture_one_actor",
"avatarBlurhash": null,
"avatarDecorations": [],
"isBot": false,
"isCat": false,
"instance": {
"name": null,
"softwareName": null,
"softwareVersion": null,
"iconUrl": null,
"faviconUrl": null,
"themeColor": null
},
"emojis": {},
"onlineStatus": "unknown"
},
"text": "no comment in attachment",
"cw": null,
"visibility": "public",
"localOnly": false,
"reactionAcceptance": null,
"renoteCount": 0,
"repliesCount": 0,
"reactions": {},
"reactionEmojis": {},
"emojis": {},
"fileIds": [
"9q9s4kmiba8v000t"
],
"files": [
{
"id": "9q9s4kmiba8v000t",
"createdAt": "2024-02-28T19:54:15.786Z",
"name": "FediverseLogo.png",
"type": "image/png",
"md5": "85e7feae66363e9e200570a28b0cf20a",
"size": 0,
"isSensitive": false,
"blurhash": "eQF5X3.}4.YJIm}ynOEUxBt89IK[N1xI-T9,TJRPX3$#ASNFo}aPtP",
"properties": {
"width": 1548,
"height": 1548
},
"url": "http://pasture_one_actor/assets/FediverseLogo.png",
"thumbnailUrl": "http://pasture_one_actor/assets/FediverseLogo.png",
"comment": "name",
"folderId": null,
"folder": null,
"userId": null,
"user": null
}
],
"replyId": null,
"renoteId": null,
"uri": "http://pasture_one_actor/actor/93ekpgPNG-w",
"clippedCount": 0
}
```