You can adjust the quality of an image by compressing the image, changing the absolute quality value, and changing the quality coefficient. Dynamic Route for CDN (DCDN) allows you to adjust the quality of images cached on DCDN nodes without changing the image format.

Note
  • Before you use image editing, you must submit a ticket to activate this feature.
  • Image editing is a paid service. It is currently free of charge until further notice.

Compress images

Automatic compression supports only the JPG and WebP formats. This feature compresses images while retaining the width, height, and format of the images. This feature is useful for reducing the data transfer volume.

Adjust image quality

Parameters

Set the action to quality.

The following table describes the parameters.
Parameter Description Valid value
Q Specifies an absolute quality value. Image quality can be represented by an absolute value. You cannot adjust the image quality to a higher value.
0<Q<100. The value must be a multiple of 5. Other values are not supported.
Note A greater quality value represents a higher quality and a higher clarity. We recommend that you set Q to 95.
q Specifies a quality coefficient. Image quality can be adjusted based on the original quality and a quality coefficient.
0<q<100. The value must be a multiple of 5. Other values are not supported.
Note A greater quality value represents a higher quality and a higher clarity. We recommend that you set Q to 95.
Examples
  • Specify an absolute quality value: If you set image_process=quality,Q_90 and the current quality is 80, the attempt to adjust the image quality from 80 to 90 fails. The image quality remains at 80.
  • Specify a quality coefficient: If you set image_process=quality,q_90 to adjust an image whose current quality is 80, the image quality is adjusted to 72.