The progressive display parameter allows an image to load in stages. This improves page loading speed and the user experience, especially for high-resolution and large images.
JPEG images can be rendered in two ways:
Top-down scan
From blurry to clear, which is noticeable on slow networks
By default, images are saved using the top-down scan method. To render an image from blurry to clear, use the progressive display parameter.
Parameter
Name | Description | Valid values |
pr | 1: Saves the image as a progressive JPEG. 0: Saves the image as a standard JPEG. | [0, 1] |
This parameter is valid only when the output image is in JPEG format.
Examples
Save an image as a progressive JPEG and scale it to 100 px in width and 200 px in height.
https://oss-console-img-demo-cn-hangzhou.oss-cn-hangzhou.aliyuncs.com/example.jpg@100w_200h_1pr.jpg
Save a PNG image as a progressive JPEG.
https://oss-console-img-demo-cn-hangzhou.oss-cn-hangzhou.aliyuncs.com/panda.png@1pr
