Introduction

After enabling the image processing function, the CDN can scale, rotate, trim, format conversion and other processing of the original image of the customer on CDN node and delivery it to end users. In this case, you can keep the original image and avoid various processing of the image on origin servers, thus reducing the workload and save storage cost on the origin, and at the same, improving the response speed of image processing.

Note:

Image processing is a paid service, it is free during the public beta test period, and the charge time will be notified.

Applicable Scenarios

Performing image processing on a CDN can eliminate the processing overhead on the origin server, enabling flexible adaptation to the varying demands of different end users for images. This is suitable for the following industry scenarios:

E-commerce Websites

The same product image may require different size trimming to fit different screen sizes, necessitating the use of image trimming functionality.
When the same product image is displayed as a thumbnail in a browsing list and as the main image after clicking the product link, different image qualities are needed, requiring the use of image quality conversion functionality.

Image Stock Websites

Image stock websites often need to apply different processing and editing to the same image, requiring the use of functions such as cropping and scaling in image processing.

Usage Limitations

The original image has the following limitations:

Currently, the supported original image formats for image processing are: JPEG, PNG, WebP, BMP, GIF, TIFF, and JP2 (JPEG2000).
The size of the original image cannot exceed 10MB; otherwise, no image processing will be performed by default.

The processed image has the following limitations:

The width multiplied by the height of the scaled image cannot exceed 16777216 px.

Configuration Instructions

This feature is not self-serviceable for now, please submit a ticket to eSurfing Cloud CDN support team to enable it.

After enabling, the image processing can be trigerred by appending query string parameters in the request URL.

Example of request URL: http://www.example.com/a.jpg?action=key1:value1&action=key2:value2。

Fields descriptions：

Parameters	Descriptions
www.example.com	Acceleration domain name.
a.jpg	The file to be processed
action	Fixed parameter name
key1:value1	Image processing parameters, for exampe, format:bmp, which represents to convert image format, convert a.jpg into bmp format.
key2:value2	Image processing parameters, support multiple actions 1.When multilple parameters are presented, getinfo has highest priority, if this parameter is presented, other parameters will be ignored. 2. When multiple parameters are presented, but not include getinfo, format conversion parameter will be the last action for processing, and other parameters will be processed in order.

For example, http://www.example.com/a.jpg?action=quality:80&action=format:bmp&action=cut:mid,w_400,h_200

Actions will be taken: convert the absolute quality of a.jpg to 80, and then trim the image by width400/height200 from the center, and convert it into bmp format.

Available parameters for image processing：

Image processing fuctions	Parameters	Descriptions
Image format conversion	format	Convert image format
Image quality conversion	quality	Support absolute and relative quality conversion
Image trimming	cut	Image trimming for specific area.
Image zooming	resize	Image zooming.
Image rotation	rotate	Image rotation.
Get image infomation	getinfo	Get info,including size, width, height, format, quality, direction,etc.

Content Delivery Network

Image processing overview