You can specify Image Processing (IMG) parameters in GetObject requests to process image objects in Object Storage Service (OSS). For example, you can add image watermarks to images or convert image formats.
OSS allows you to use one or more parameters to process images. You can also specify multiple IMG parameters in a style to process images at a time. For more information about image styles, see Image styles.
If you specify multiple IMG parameters, OSS processes the image in the order of the parameters. The following table describes IMG parameters.
|Resize images||resize||Resizes images.|
|Add watermarks||watermark||Adds image watermarks or text watermarks to images.|
|Custom crop||crop||Crops rectangular images based on the specified size.|
|Adjust image quality||quality||Adjusts the quality of images in the JPG format and WebP format.|
|Convert image formats||format||Converts the formats of images to specified formats.|
|Query the EXIF data of an image||info||Obtains image information, including basic information and Exchangeable Image File Format (EXIF) information.|
|Auto-rotate||auto-orient||Auto-rotates images for which the auto-orient parameter is configured.|
|Circle crop||circle||Crops images into circles of the specified size based on the center point of images.|
|Indexed slice||indexcrop||Crops images along the specified horizontal axis or vertical axis and selects one of the images.|
|Rounded rectangle||rounded-corners||Crops images into rounded rectangles based on the specified rounded radius size.|
|Rotate||rotate||Rotates images clockwise by a specified angle.|
|Gradual display||interlace||Configures gradual display for JPG images.|
|Query the average tone||average-hue||Queries the average hue of images.|
|Brightness||bright||Adjusts the brightness of images.|
|Contrast||contrast||Adjusts the contrast of images.|
qualityparameters to process the
example.jpgimage, the URL of the image is
https://image-demo.oss-cn-hangzhou.aliyuncs.com/example.jpg?x-oss-process=image/resize,w_300/quality,q_90. You can configure CDN back-to-origin rules to filter out or retain the IMG parameters contained in the URLs of images that you want to retrieve. This way, you can retrieve source images or images that are processed by using IMG parameters.
- Retrieve source images
You can enable the parameter filtering feature of CDN to filter out all parameters that follow the question mark (?) in the URL of the image that you want to retrieve. In this example, the
example.jpgsource image is retrieved.
- Retrieve processed images
You can enable the parameter retaining feature of CDN to retain all parameters that follow the question mark (?) in the URL of the image that you want to retrieve. In this example, the processed image is retrieved.
For more information about how to configure CDN back-to-origin rules, see Ignore parameters.
You can use object URLs, API operations, and SDKs to process images. For more information, see IMG implementation modes.
|Image size||The size of a source image cannot exceed 20 MB.|
|Image width and height||For the rotate operation, the height or width of the source image cannot exceed 4,096 pixels. For other operations, the width or height of the source image cannot exceed 30,000 pixels, and the total pixel number of the source image cannot exceed 250 million. |
The total pixel number of a dynamic image, such as a GIF image, is calculated based on the following formula:
|Image compression||The width or height of a compressed image cannot exceed 16,384 pixels. The total pixel number of a compressed image cannot exceed 16,777,216.|
|Advanced image compression||The number of pixels of a compressed HEIC image cannot exceed 4,096 × 4,096. The number of pixels of a compressed AVIF image cannot exceed 4,096 × 2,304.|
|Image styles||You can create up to 50 image styles for a bucket. If your business requires more than 50 styles for a bucket, submit a ticket.|
- API operation calling fees
A GetObject request is generated each time you use IMG to process an image. You are charged based on the number of generated requests. For more information about API operation calling fees, see API operation calling fees.
- Traffic fees
You are charged for the outbound traffic over the Internet based on the size of the processed images. For more information about traffic fees, see Traffic fees.
IMG provides two versions of API operations. This topic describes the new version of the API operations. Update support is no longer provided for the old version. For more information about the compatibility between the new and old versions of API operations, see FAQ on using old and new versions of APIs and domain names.