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": [
"http://misskey/users/9qdq8d9d6c3i0001",
"https://www.w3.org/ns/activitystreams#Public"
],
"id": "http://pasture_one_actor/actor/G8voplWVPIw",
"object": {
"type": "Note",
"attributedTo": "http://pasture_one_actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://misskey/users/9qdq8d9d6c3i0001"
],
"id": "http://pasture_one_actor/actor/pfuaMAtVRBE",
"published": "2024-03-02T14:14:29Z",
"content": "no description",
"attachment": {
"type": "Document",
"url": "http://pasture_one_actor/images/100.png"
}
}
}
```
```json title="misskey"
{
"id": "9qdqb62wkaol000q",
"createdAt": "2024-03-02T14:14:29.000Z",
"userId": "9qdq9vhakaol0002",
"user": {
"id": "9qdq9vhakaol0002",
"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": [
"9qdqb6afkaol000p"
],
"files": [
{
"id": "9qdqb6afkaol000p",
"createdAt": "2024-03-02T14:14:29.271Z",
"name": "100.png",
"type": "image/png",
"md5": "dba345640dab05c137c9e96253f958fb",
"size": 0,
"isSensitive": false,
"blurhash": "e0Fhh8~TfQ~TfQ~Tj[fQj[fQfQfQfQfQfQ~Tj[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/pfuaMAtVRBE",
"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": [
"http://misskey/users/9qdq8d9d6c3i0001",
"https://www.w3.org/ns/activitystreams#Public"
],
"id": "http://pasture_one_actor/actor/gGSKwM2Km5o",
"object": {
"type": "Note",
"attributedTo": "http://pasture_one_actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://misskey/users/9qdq8d9d6c3i0001"
],
"id": "http://pasture_one_actor/actor/fbaBdxIDDt4",
"published": "2024-03-02T14:14:31Z",
"content": "text",
"attachment": {
"type": "Document",
"url": "http://pasture_one_actor/images/100.png",
"name": "name",
"summary": "summary",
"content": "content"
}
}
}
```
```json title="misskey"
{
"id": "9qdqb7mgkaol000s",
"createdAt": "2024-03-02T14:14:31.000Z",
"userId": "9qdq9vhakaol0002",
"user": {
"id": "9qdq9vhakaol0002",
"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": [
"9qdqb7vhkaol000r"
],
"files": [
{
"id": "9qdqb7vhkaol000r",
"createdAt": "2024-03-02T14:14:31.325Z",
"name": "100.png",
"type": "image/png",
"md5": "f9b9cc5c74955f256964429d4223888d",
"size": 0,
"isSensitive": false,
"blurhash": "e0BNfa?tfQ?tfQ?tj[fQj[fQfQfQfQfQfQ?tj[fQj[fQfQfQfQfQfQ",
"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/fbaBdxIDDt4",
"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": [
"http://misskey/users/9qdq8d9d6c3i0001",
"https://www.w3.org/ns/activitystreams#Public"
],
"id": "http://pasture_one_actor/actor/qQUoEHoA3g8",
"object": {
"type": "Note",
"attributedTo": "http://pasture_one_actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://misskey/users/9qdq8d9d6c3i0001"
],
"id": "http://pasture_one_actor/actor/QWloaAPa-Rc",
"published": "2024-03-02T14:14:33Z",
"content": "text",
"attachment": [
{
"type": "Document",
"url": "http://pasture_one_actor/assets/FediverseLogo.png",
"name": "name",
"imageType": "image/jpeg"
}
]
}
}
```
```json title="misskey"
{
"id": "9qdqb960kaol000u",
"createdAt": "2024-03-02T14:14:33.000Z",
"userId": "9qdq9vhakaol0002",
"user": {
"id": "9qdq9vhakaol0002",
"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": [
"9qdqb9k9kaol000t"
],
"files": [
{
"id": "9qdqb9k9kaol000t",
"createdAt": "2024-03-02T14:14:33.513Z",
"name": "FediverseLogo.png",
"type": "image/png",
"md5": "85e7feae66363e9e200570a28b0cf20a",
"size": 0,
"isSensitive": false,
"blurhash": "eQE_?c.}4.YJM^}fi{EVw[xu9JK[M~xI-T9+TJRPX2$$E]NFo}j1tO",
"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/QWloaAPa-Rc",
"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": [
"http://misskey/users/9qdq8d9d6c3i0001",
"https://www.w3.org/ns/activitystreams#Public"
],
"id": "http://pasture_one_actor/actor/4aVoi2jXfhE",
"object": {
"type": "Note",
"attributedTo": "http://pasture_one_actor/actor",
"to": [
"https://www.w3.org/ns/activitystreams#Public",
"http://misskey/users/9qdq8d9d6c3i0001"
],
"id": "http://pasture_one_actor/actor/V8V0Mcj4U28",
"published": "2024-03-02T14:14:35Z",
"content": "no comment in attachment",
"attachment": [
{
"type": "Document",
"url": "http://pasture_one_actor/assets/FediverseLogo.png"
}
]
}
}
```
```json title="misskey"
{
"id": "9qdqbapkkaol000v",
"createdAt": "2024-03-02T14:14:35.000Z",
"userId": "9qdq9vhakaol0002",
"user": {
"id": "9qdq9vhakaol0002",
"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": [
"9qdqb9k9kaol000t"
],
"files": [
{
"id": "9qdqb9k9kaol000t",
"createdAt": "2024-03-02T14:14:33.513Z",
"name": "FediverseLogo.png",
"type": "image/png",
"md5": "85e7feae66363e9e200570a28b0cf20a",
"size": 0,
"isSensitive": false,
"blurhash": "eQE_?c.}4.YJM^}fi{EVw[xu9JK[M~xI-T9+TJRPX2$$E]NFo}j1tO",
"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/V8V0Mcj4U28",
"clippedCount": 0
}
```