add text watermarks and image watermarks to images - Edge Security Acceleration

Parameters

image_process=watermark

Basic parameters (watermark positions)

Parameter	Description	Value range
t	The opacity of the watermark.	`[0,100]` Default value: `100`. A value of 100 specifies that the watermark is fully opaque.
g	The position of the watermark on the image.	nw: upper left north: upper middle ne: upper right west: middle left center: center east: middle right sw: lower left south: lower middle se: lower right
x	The horizontal margin between the watermark and the image edge. This parameter takes effect only when the watermark is at the left or right side of the image.	`[0,4096]` Default value: `10`. Unit: `px`.
y	The vertical margin between the watermark and the image edge. This parameter takes effect only when the watermark is at the top or bottom of the image.	`[0,4096]` Default value: `10`. Unit: `px`.

Note

You can use x, y, and offset to adjust watermark positions. These parameters also help arrange layouts when an image has multiple watermarks.

Image watermark parameters

Parameter

Description

Value range

image

The URL of the watermark image, which must be publicly accessible. If the URL requires authentication or specific permissions, ESA may fail to retrieve the image.

The URL must be Base64-encoded. For more information, see Encode watermarks.

Base64-encoded strings

Text watermark parameters

Parameter	Description	Value range
text	The text watermark content, which must be Base64-encoded. For more information, see Encode watermarks.	A Base64-encoded string of up to 60 characters
type	The font of the text watermark, which must be Base64-encoded. For more information, see Encode watermarks.	You can specify up to 10 fonts. For information about supported fonts and their encoded values, see type settings and encoding.
color	The color of the text watermark, specified as an RGB hex value.	For example, 000000 specifies black, and FFFFFF specifies white. Default value: `000000`.
rotate	The clockwise rotation angle of the text watermark.	`[0,360]` Default value: `0`. A value of 0 means no rotation. Unit: °.
fill	Specifies whether to tile the image with the text watermark.	Valid values: `0` and `1`. Default value: `0`. 0: does not tile the image with the text watermark. 1: tiles the image with the text watermark.
size	The font size of the text watermark.	`[1,1000]` Default value: `40`. Unit: `px`.

type settings and encoding

Text font	Description	Encoded value
alihyaihei	A bold font. This is the default font.	YWxpaHlhaWhlaQ
hysong	A Songti font variant.	aHlzb25n
hyhei	A Heiti font variant.	aHloZWk
hyshuangxian	A double line font.	aHlzaHVhbmd4aWFu
fzltzhk	A Heiti font variant.	ZnpsdHpoaw
fzshengsks	A regular script font.	ZnpzaGVuZ3Nrcw
fzqusongjian	A Songti font variant.	ZnpxdXNvbmdqaWFu
zzgfxingyan	An artistic font.	enpnZnhpbmd5YW4
comfortaa	Comfortaa	Y29tZm9ydGFh
notosans	NotoSans	bm90b3NhbnM

Note

If you specify a font not in the list above, the default font alihyaihei is used.

Encode watermarks

When you add watermarks, you must Base64-encode the text content and font name, or the image watermark URL, using URL-safe characters. To encode watermarks, perform the following steps:

Encode the watermark content in Base64.

Note

We recommend that you use URL-safe Base64 encoding tools to encode the text content, font names, and image watermark URLs. Base64-encoded watermark content applies only to watermark-specific parameters. Do not include Base64-encoded watermark content in signature strings.

Replace characters in the Base64-encoded watermark content based on the following rules:
- Replace the plus signs (+) with hyphens (-).
- Replace the forward slashes (/) with underscores (_).
- Omit the equal signs (=) at the end of the Base64-encoded watermark content.

Examples

Add the "Hello World" text watermark.

Encode the Hello World text watermark in URL-safe Base64. For more information, see Encode watermarks. The encoded text is SGVsbG8gV29ybGQ. The encoded hysong font value is aHlzb25n. The image processing URL is http(s)://example.com/image01.png?image_process=watermark,text_SGVsbG8gV29ybGQ,type_aHlzb25n.

Add text and image watermarks.
- Encode the "Happy New Year" text watermark in URL-safe Base64 to get the 5paw5bm05b-r5LmQ string. Set the watermark position to lower right, horizontal margin to 10 pixels, and vertical offset to 10 pixels by using g_se,x_10,y_10.
- Encode the http://example-test.oss-ap-southeast-1.aliyuncs.com/image/shuiyin.png image watermark URL in URL-safe Base64 to get the aHR0cDovL2V4YW1wbGUtdGVzdC5vc3MtYXAtc291dGhlYXN0LTEuYWxpeXVuY3MuY29tL2ltYWdlL3NodWl5aW4ucG5n string. Set the watermark position to upper left, horizontal margin to 10 pixels, and vertical offset to 10 pixels by using g_nw,x_10,y_10.
- Specify the image processing URL as http(s)://example.com/image01.png?image_process=watermark,text_5paw5bm05b-r5LmQ,g_se,x_10,y_10/watermark,image_aHR0cDovL2V4YW1wbGUtdGVzdC5vc3MtYXAtc291dGhlYXN0LTEuYWxpeXVuY3MuY29tL2ltYWdlL3NodWl5aW4ucG5n,g_nw,x_10,y_10.