Original images on content sharing websites need to be resized, cropped, rotated, or compressed based on business requirements. If an image is retrieved from the origin server each time the image is edited, loads on the origin server and cache on points of presence (POPs) increase. Alibaba Cloud CDN provides the image editing feature, which allows you to edit images and cache the edited images on POPs. This accelerates content delivery, reduces loads on origin servers, and lowers origin traffic.
The image editing feature of Alibaba Cloud CDN, the image editing feature of DCDN, and the Image Processing (IMG) feature of Object Storage Service (OSS) are three different features.
Image editing is a paid service and is free of charge until further notice.
After you enable image editing, images are edited and cached on POPs. This reduces loads on origin servers.
The following table describes some common scenarios.
Websites that provide design resources
Image editing provides the following benefits:
After a source image is cached on POPs, the image is resized based on requests and the resized image is directly returned to clients. This improves image distribution.
Reduced loads on origin servers
If images are edited and stored on origin servers, the images consume the storage and computing resources of the origin servers and increase the maintenance cost of the origin servers. After you enable image editing, images are edited and cached on POPs. This reduces loads on origin servers.
Improved refresh and prefetch efficiency
After a source image expires, all images that are edited based on the source image are expired and become unavailable. To address this issue, images are edited and cached on POPs. This solution reduces the frequency of refresh and prefetch tasks and the amount of bandwidth resources consumed by requests that are redirected to origin servers. Newly edited images are cached on POPs to ensure the availability of source images and edited images.
Image editing on POPs
This feature can recognize image editing parameters and edit images to adapt to different browsers and clients. This helps meet the requirements of different users.
When you use image editing, take note of the following limits:
Limits on source images
Only the following image formats are supported: JPEG, JPG, PNG, WebP, BMP, GIF, TIFF, and JPEG 2000.
The size of a source image cannot exceed 10 MB.
The total pixels of a source image cannot exceed 16,777,216 pixels.Note
If a source image is in the GIF format, the product of height and the width is the sum of all frames. You can use tools, such as ImageMagick, to view the frames of GIF images.
Limits on edited images
The total pixels of an edited image cannot exceed 16,777,216 pixels.
If you want to convert an edited image to the WebP format, the total pixels of the image cannot exceed 16,777,216 pixels. The width or height of the image cannot exceed 16,384 pixels. If a source image is a dynamic image, a static image is generated when you convert the source image to the WebP format.
Enable and use image editing
For information, see Enable and use image editing.