Alibaba Cloud CDN image editing lets you resize, crop, rotate, compress, and convert images directly at Points of Presence (POPs), without sending requests back to your origin server. Edited images are cached on POPs and served to clients on subsequent requests.
CDN image editing, DCDN image editing, and Object Storage Service (OSS) Image Processing (IMG) are three separate features. Image editing is free of charge until further notice.
How it works
A client requests an image with editing parameters appended to the URL.
The POP applies the requested edits and caches the edited image.
Subsequent requests for the same edited image are served directly from the POP cache, without hitting your origin server.
This eliminates redundant origin requests, reduces the load on your origin server, and lowers origin traffic costs.
Use cases
Industry | What you can do |
E-commerce | Generate product images in multiple sizes for different devices; add brand watermarks; compress product and review images to cut traffic costs |
Social media | Convert images to standard formats for posting; add watermarks to prevent image theft |
Online education | Edit and compress course images to balance quality and delivery cost |
Design resources | Compress high-resolution images without visible quality loss for faster delivery |
Benefits
Faster delivery
Edited images are cached on POPs and served from the cache on repeated requests, eliminating unnecessary round-trips to the origin server.
Lower origin load
Image processing on an origin server consumes storage and compute resources. Offloading editing and caching to POPs reduces that strain and lowers maintenance costs.
Fewer purge and prefetch operations
POP-cached edited images remain available even when the source image expires. This reduces the frequency of purge and prefetch tasks and the bandwidth consumed by origin requests.
Device-adaptive editing
Append editing parameters to image URLs to deliver images optimized for specific browsers or client devices.
Limitations
Source images
Constraint | Limit |
Supported formats | JPEG, JPG, PNG, WebP (single-frame), BMP, GIF (only resize and refomat are supported for multi-frame), TIFF, JPEG 2000 |
Maximum file size | 10 MB |
Maximum pixel count | 16,777,216 pixels |
For GIF images, the pixel count is the sum of pixels across all frames. Use a tool such as ImageMagick to inspect frame information.
Edited images
Constraint | Limit |
Maximum pixel count | 16,777,216 pixels |
WebP output: maximum pixel count | 16,777,216 pixels |
WebP output: maximum width or height | 16,384 pixels per side |
WebP output: dynamic source images | Converted to a static image |
Format conversion
Converting between formats may increase file size because different formats use different compression algorithms. For example, converting JPEG to WebP, JPEG to PNG, or PNG to WebP can produce a larger output. To reduce the output file size, set the quality parameter to lower the image quality.