Image compression refers to reducing an image’s size as much as possible without changing its quality, to reduce its cost for storage and traffic and speed up access.
CI launched the TPG compression feature to convert images into TPG format, a Tencent-developed format with animated image support. Currently, products such as QQ Browser and Qzone have TPG support by default. TPG offers over 90% smaller file sizes at the same quality compared with GIF, and over 50% smaller file sizes compared with PNG.
CI uses the imageMogr2 API to provide the TPG compression feature.
An image can be processed:
Note:TPG compression is billed at image advanced compression rates by CI.
download_url?imageMogr2/format/tpg
PUT /<ObjectKey> HTTP/1.1
Host: <BucketName-APPID>.cos.<Region>.myqcloud.com
Date: GMT Date
Authorization: Auth String
Pic-Operations:
{
"is_pic_info": 1,
"rules": [{
"fileid": "exampleobject",
"rule": "imageMogr2/format/tpg"
}]
}
POST /<ObjectKey>?image_process HTTP/1.1
Host: <BucketName-APPID>.cos.<Region>.myqcloud.com
Date: GMT Date
Content-length: Size
Authorization: Auth String
Pic-Operations:
{
"is_pic_info": 1,
"rules": [{
"fileid": "exampleobject",
"rule": "imageMogr2/format/tpg"
}]
}
Note:Processing upon download is used as an example here, which does not store the output image in a bucket. If you need to store the output image, use Processing upon upload or Processing in-cloud data instead.
Parameter | Description |
---|---|
download_url | URL of the input image, formatted as &dxlt;BucketName-APPID>.cos.&dxlt;Region>.myqcloud.com/&dxlt;picture name> Example: examplebucket-1250000000.cos.ap-shanghai.myqcloud.com/picture.jpeg |
/format/&dxlt;Format> | Compression format, which is tpg |
Assume that the input image is a 1,335.2 KB image in PNG format, as shown below:
You can convert the image into TPG format using the following URL:
http://example-1258125638.cos.ap-shanghai.myqcloud.com/sample.png?imageMogr2/format/tpg
Compression ratio comparison
Format | Image Size |
---|---|
PNG (input image) | 1,335.2 KB |
TPG | 36.67 KB (compression ratio: 97.3%) |
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