OSS IMG parameters, methods, and limitations - Object Storage Service

IMG parameters

Process images with one or more parameters, or group parameters into a style for batch processing. Image styles.

When you specify multiple IMG parameters, OSS processes the image in the specified order.

Actions	Parameter	Description
Image resizing	resize	Resizes the image to specified dimensions.
Watermarking	watermark	Adds an image or text watermark to the image.
Custom cropping	crop	Crops the image into a rectangle of a specified size.
Quality adjustment	quality	Adjusts the quality of JPG and WebP images.
Format conversion	format	Converts the image format.
Advanced compression for HEIF or AVIF images	format	Converts the image to a high-compression format, such as HEIF or AVIF.
Query image information	info	Retrieves image information, such as basic properties and Exchangeable Image File Format (EXIF) data.
Auto orientation	auto-orient	Automatically rotates an image based on its orientation metadata.
Circular crop	circle	Crops a circular image of a specified size, centered on the original image.
Indexed slice	indexcrop	Slices the image into sections along the x-axis or y-axis and selects one of the slices.
Rounded rectangle	rounded-corners	Crops the image into a rectangle with rounded corners of a specified radius.
Blur	blur	Applies a blur effect to the image.
Rotation	rotate	Rotates the image clockwise by a specified angle.
Set display mode	interlace	Enables progressive rendering for an image in JPG format.
Get average hue	average-hue	Retrieves the average hue of the image.
Brightness	bright	Adjusts the brightness of the image.
Sharpen	sharpen	Applies a sharpening effect to the image.
Contrast	contrast	Adjusts the contrast of the image.

For example, adding resize and quality parameters to example.jpg produces the URL https://oss-console-img-demo-cn-hangzhou.oss-cn-hangzhou.aliyuncs.com/example.jpg?x-oss-process=image/resize,w_300/quality,q_90. You can configure CDN to retrieve either the source or processed image during back-to-origin requests.

Back-to-origin for the source image

With parameter filtering enabled, CDN strips all parameters after the question mark (?) and fetches the source image example.jpg.
Back-to-origin for the processed image

With parameter preservation, CDN retains the URL parameters and fetches the processed image.

Configure CDN back-to-origin rules with Ignore parameters.

IMG methods

Process images using object URLs, API operations, or SDKs. Image processing methods.

Limitations

Item	Description
Image formats	The source image must be in one of the following formats: JPG, PNG, BMP, GIF, WebP, TIFF, HEIC, or AVIF. For dynamic images such as animated GIFs, only resizing, cropping, rotation, and watermarking are supported. To encode or decode animated WebP images, submit a ticket.
Image size	Maximum source image size: 20 MB.
Source image dimensions	Rotation: maximum width or height is 4,096 px. Other operations: maximum width or height is 30,000 px, with a total pixel limit of 250 million. The total number of pixels for dynamic images, such as GIF images, is `width * height * number of frames`, while for static images, such as PNG images, it is `width * height`.
Target image dimensions	For WebP images, the width and height cannot exceed 16,383 px. For HEIC images, the width and height cannot exceed 4,096 px. For AVIF images, the width cannot exceed 4,096 px, and the total number of pixels cannot exceed 9,437,184.
Image resizing	After resizing, the width or height cannot exceed 16,384 px, and total pixels cannot exceed 16,777,216.
Image styles	Maximum: 50 image styles per bucket. To request more, submit a ticket. Note A single image style can include multiple IMG parameters for complex operations. Image styles.
Processing capacity	Image processing throughput per second (based on source image size) China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), and China (Shenzhen): 20 MB/s. Other regions: 2 MB/s. Queries per second (QPS) China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), and China (Shenzhen): 50. Other regions: 5. Note For computationally intensive scenarios (encoding WebP, AVIF, or HEIF above 1080p) or workloads exceeding these limits, contact technical support to evaluate limits for your use case.

Billing

IMG incurs the following fees:

Request fees

Each operation generates one GetObject request, incurring a per-request fee. Request fees.
Traffic fees

Outbound traffic fees are based on processed image size. Traffic fees.

IMG versions

IMG has both a new and old API version. This document covers the new version; the old version is no longer updated. New and old versions of IMG and their compatibility.