Image Watermarks

Last updated: 2020-06-11 16:37:59


    This API watermark from Tencent Cloud CI is used to provide image watermarking in COS. Currently, watermark images must be those stored in buckets associated with CI. Supported original images must be smaller than 20 MB in size and smaller than 9,999 pixels in length and width.

    Image processing is a paid service, the fees of which are charged by Cloud Infinite. For detailed billing instructions, see Cloud Infinite’s [Billing and Pricing] (

    API Form


    Please ignore the preceding spaces and line breaks.

    Parameter Description

    Operation name: watermark. 1 indicates that the watermark is an image watermark.

    Parameter Description
    download_url URL that is used to access a file. Format: <BucketName-APPID>.cos.<picture region>.<domain>.com/<picture name>,
    such as
    /image/ The URL of the watermark image, which must be URL-safe Base64 encoded. For example, the watermark image is, and the encoded string is aHR0cDovL2V4YW1wbGVidWNrZXQtMTI1MDAwMDAwMC5jb3MuYXAtc2hhbmdoYWkubXlxY2xvdWQuY29tL3NodWl5aW5fMi5wbmc.
    /gravity/ Text watermark position, which is shown in a 3 x 3 grid (See the 3 x 3 positioning grid). The default value is SouthEast.
    /dx/ Horizontal margin in pixels. The default value is 0.
    /dy/ Vertical margin in pixels. The default value is 0.
    /blogo/ The watermark image adaptation feature, which is applicable to scenarios in which the watermark image size is too large, for example, a watermark wall. There are two options:
  • When blogo is set to 1, the watermark image is scaled to a size similar to that of the original image and then added.
  • When blogo is set to 2, the watermark image is directly cropped to a size similar to that of the original image and then added.
  • A specified watermark image must meet the following conditions:

    • The watermark image and the source image must be located in the same bucket.
    • The URL must be a domain name of the CI origin server (and cannot be a CDN acceleration or COS origin server domain name). For example, is a CDN acceleration domain name, and therefore cannot be used as a watermark URL.
    • The URL must start with http://. The HTTP header cannot be omitted or replaced by an HTTPS header. For example, and are invalid watermark URLs.

    3 x 3 Positioning Grid

    A 3 x 3 positioning grid provides position reference for multiple image operations. Red dots show the origin points of each region. After you use the gravity parameter to select a region, displacement must be based on the corresponding farthest point.

    • When gravity is set to center, the dx and dy parameters are invalid.
    • When gravity is set to north or south, the dx parameter is invalid (in which case the watermark is horizontally centered).
    • When gravity is set to west or east, the dy parameter is invalid (in which case the watermark is vertically centered).


    This example shows you how to add an image watermark.

    Final image:

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