tencent cloud

Feature Overview

Blind watermarking is a brand-new watermarking feature based on Tencent Cloud CI. It allows you to add a watermark to the input image information without displaying the watermark or significantly affecting the image quality. If you suspect that your image has been stolen, you can extract the blind watermark from the suspected image to check whether the image belongs to you.

You can call this API to:

• Add a blind watermark to an image upon upload.
• Add a blind watermark to an image upon download.
• Add a blind watermark to an image stored in COS.

You can also extract the blind watermark from a watermarked image.

Note：

• Currently, you cannot add a blind watermark to animated images such as GIF.
• Both the width and height of the image watermark must not be greater than 1/8 of the input image.
• You need to choose a white watermark with a black background for the effect of blind watermarking.
• Text watermarks can contain digits and letters.
• Blind watermarking protects your images against various theft attacks such as cropping, smudging, and color change. The anti-theft effect is affected by the size of the input image and the attack intensity. For details, please submit a ticket.
• Blind watermarking is supported in all regions of CI. For more information, see Regions and Domain Names.

  Adding Blind Watermarks

Request 1: adding a blind watermark upon upload

The request is the same as that in a PUT Object call, except that you need to add the image processing parameter Pic-Operations to the request header and use blind watermarking parameters.

Sample request

PUT /<ObjectKey> HTTP/1.1
Host: <BucketName-APPID>.cos.<Region>.myqcloud.com
Date: GMT Date
Authorization: Auth String
Pic-Operations: <PicOperations>

[Object Content]

Note：

Authorization: Auth String (See Request Signature for details.)

Request headers

This API uses Common Request Headers.

Add the image processing parameter Pic-Operations (a JSON string) to the request header. Its parameters are as follows:

Parameter	Description	Type	Required
is_pic_info	Whether to return the input image information 0 (default): no 1: yes	Int	No
rules	Processing rules (up to five rules are supported). Each rule corresponds to one processing result. If this parameter is not specified, images will not be processed.	Array	No

Parameters of rules (a JSON array) are as follows:

Parameter	Description	Type	Required
bucket	Name of the destination bucket to store the results, formatted as BucketName-APPID. If this parameter is not specified, the results will be stored in the current bucket.	String	No
fileid	The path and name of the output file The rules for setting this parameter are as follows (assume that the input file is stored in /p1/test1.jpg): 1. A value starting with a slash (/) indicates an absolute path. For example, if fileid is set to /p2/test2.jpg, the test2.jpg file will be stored in the p2 folder. 2. A value not starting with a slash indicates a relative path. For example, if fileid is set to p2/test2.jpg, a folder named p2 is created in the p1 folder, and the test2.jpg file will be stored in the p2 folder. 3. Note: Do not end the value with a slash. Otherwise, an empty filename will be generated.	String	Yes
rule	Processing parameters. For more information, see the image processing API. To process an image using a specified style, the value must start with style/ with the style name followed. For example, if the style name is test, the value of rule should be style/test.	String	Yes

To use blind watermarking, add the watermarking parameter watermark to rule as follows:

watermark/3/type/<type>/image/<imageUrl>/text/<text>/level/<level>

The parameters are as follows:

Parameter	Description	Type	Required
type	Blind watermarking type. Valid values: 1 (semi-blind watermarking), 2 (perfectly blind watermarking), 3 (text blind watermarking)	Int	Yes
image	URL of the blind image watermark, which must be URL-safe Base64-encoded. This parameter is required if type is set to 1 or 2, and does not take effect if type is set to 3. The image watermark must: 1. Be stored in the same bucket as the input image. 2. Have a URL that starts with http://. Note that "http://" cannot be omitted or changed to "https://". For example, the following watermark URLs are invalid: examplebucket-1250000000.cos.ap-shanghai.myqcloud.com/watermark.png https://examplebucket-1250000000.cos.ap-shanghai.myqcloud.com/watermark.png	String	No
text	Text watermark, which must be URL-safe Base64-encoded. This parameter is required if type is set to 3 and does not take effect if type is set to 1 or 2.	String	No
level	Perfectly blind watermarking level, which only takes effect when type is set to 2. Valid values: 1 (default), 2, 3. The larger the value, the better the watermarking effects.	Int	No

Request parameters

This API has no request parameter.

Request body

The request body of this API is the content of the input image.

Response

Response headers

This API only returns Common Response Headers.

Response body

Parameters in the response body are as follows:

Parameter	Description	Type
UploadResult	Upload results	Container

Content of UploadResult:

Parameter	Description	Type
OriginalInfo	Information about the input image	Container
ProcessResults	Processing results	Container

Content of OriginalInfo:

Parameter	Description	Type
Key	Name of the input image	String
Location	Image location	String
ImageInfo	Information about the input image	Container

Content of ImageInfo:

Parameter	Description	Type
Format	Image format	String
Width	Image width	Int
Height	Image height	Int
Quality	Image quality	Int
Ave	Image average hue	String
Orientation	Image rotation angle	Int

Content of ProcessResults:

Parameter	Description	Type
Object	Processing results of each image	Container

Content of Object:

Parameter	Description	Type
Key	Filename	String
Location	Image location	String
Format	Image format	String
Width	Image width	Int
Height	Image height	Int
Size	Image size	Int
Quality	Image quality	Int

Example

Request

PUT /exampleobject HTTP/1.1
Host: examplebucket-1250000000.cos.ap-chengdu.myqcloud.com
Date: Tue, 03 Apr 2018 09:06:15 GMT
Authorization:XXXXXXXXXXXX

Pic-Operations:
{
    "is_pic_info": 1,
    "rules": [{
        "fileid": "exampleobject",
        "rule": "watermark/3/type/1/image/aHR0cDovL2V4YW1wbGVzLTEyNTEwMDAwMDQucGljc2gubXlxY2xvdWQuY29tL3NodWl5aW4uanBn"
    }]
}
Content-Length: 64

[Object Content]

Response

HTTP/1.1 200 OK
Content-Type: application/xml
Content-Length: 645
Date: Tue, 03 Apr 2018 09:06:16 GMT
Status: 200 OK
x-cos-request-id: NWFjMzQ0MDZfOTBmYTUwXzZkZV8z****

<UploadResult>
          <OriginalInfo>
              <Key>exampleobject</Key>
              <Location>examplebucket-1250000000.cos.ap-chengdu.myqcloud.com/exampleobject</Location>
              <ImageInfo>
                   <Format>JPEG</Format>
                   <Width>640</Width>
                   <Height>427</Height>
                   <Quality>100</Quality>
                   <Ave>0xa18454</Ave>
                   <Orientation>1</Orientation>
              </ImageInfo>
          </OriginalInfo>
          <ProcessResults>
              <Object>
                   <Key>exampleobject</Key>
                   <Location>examplebucket-1250000000.cos.ap-chengdu.myqcloud.com/exampleobject</Location>
                   <Format>png</Format>
                   <Width>640</Width>
                   <Height>427</Height>
                   <Size>463092</Size>
                   <Quality>100</Quality>
              </Object>
          </ProcessResults>
</UploadResult>

Note：

• [Object Content] in the request body is the binary string of the input image, and imageUrl in rule in the request header Pic-Operations is the URL of the image watermark.
• Location in ProcessResults in the response body is the URL of the image with a blind watermark.

Request 2: adding a blind watermark upon download

You can add a blind watermark upon download in the same way as adding a regular watermark, except that you need to use the watermark parameter after the image URL.

Sample request

GET /<ObjectKey>?watermark/3/type/<type>/image/<imageUrl>/text/<text> HTTP/1.1
Host: <BucketName-APPID>.cos.<Region>.myqcloud.com
Date: <GMT Date>
Authorization: <Auth String>

Request parameters

The request parameters are as follows:

Parameter	Description	Type	Required
download_url	URL of the input image, formatted as http(s)://<bucketname-appid>.cos.<region>.myqcloud.com/<picture name="">. Example: examplebucket-1250000000.cos.ap-shanghai.myqcloud.com/picture.jpeg	String	Yes
type	Blind watermarking type. Valid values: 1 (semi-blind watermarking), 2 (perfectly blind watermarking), 3 (text blind watermarking)	Int	Yes
image	URL of the blind image watermark, which must be URL-safe Base64 encoded. This parameter is required if type is set to 1 or 2, and does not take effect if type is set to 3. The image watermark must: 1. Be stored in the same bucket as the input image. 2. Have a URL that starts with http://. Note that "http://" cannot be omitted or changed to "https://". For example, the following watermark URLs are invalid: examplebucket-1250000000.cos.ap-shanghai.myqcloud.com/watermark.png https://examplebucket-1250000000.cos.ap-shanghai.myqcloud.com/watermark.png	String	No
text	Text watermark, which must be URL-safe Base64-encoded. This parameter is required if type is set to 3 and does not take effect if type is set to 1 or 2.	String	No
level	Perfectly blind watermarking level, which only takes effect when type is set to 2. Valid values: 1 (default), 2, 3. The larger the value, the better the watermarking effects.	Int	No

Example

https://examplebucket-1250000000.cos.ap-shanghai.myqcloud.com/sample.jpeg?watermark/3/type/3/text/dGVuY2VudCBjbG91ZA==

Request 3: adding a blind watermark to an image stored in COS

You can call this API to add a blind watermark to an image stored in COS and save the result to COS.

Sample request

POST /<ObjectKey>?image_process HTTP/1.1
Host: <BucketName-APPID>.cos.<Region>.myqcloud.com
Date: GMT Date
Authorization: Auth String
Pic-Operations: <PicOperations>

Note：

Authorization: Auth String (see Request Signature for more information).

Request headers

This API uses Common Request Headers.

Add the image processing parameter Pic-Operations (a JSON string) to the request header. Its parameters are as follows:

Parameter	Description	Type	Required
is_pic_info	Whether to return the input image information 0 (default): no 1: yes	Int	No
rules	Processing rules (up to five rules are supported). Each rule corresponds to one processing result. If this parameter is not specified, images will not be processed.	Array	No

Parameters of rules (a JSON array) are as follows:

Parameter	Description	Type	Required
bucket	Name of the destination bucket to store the results, formatted as BucketName-APPID. If this parameter is not specified, the results will be stored in the current bucket.	String	No
fileid	The path and name of the output file The rules for setting this parameter are as follows (assume that the input file is stored in /p1/test1.jpg): 1. A value starting with a slash (/) indicates an absolute path. For example, if fileid is set to /p2/test2.jpg, the test2.jpg file will be stored in the p2 folder. 2. A value not starting with a slash indicates a relative path. For example, if fileid is set to p2/test2.jpg, a folder named p2 is created in the p1 folder, and the test2.jpg file will be stored in the p2 folder. 3. Note: Do not end the value with a slash. Otherwise, an empty filename will be generated.	String	Yes
rule	Processing parameters. For more information, see the image processing API. To process an image using a specified style, the value must start with style/ with the style name followed. For example, if the style name is test, the value of rule should be style/test.	String	Yes

To use blind watermarking, add the watermarking parameter watermark to rule as follows:

watermark/3/type/<type>/image/<imageUrl>/text/<text>/level/<level>

The parameters are as follows:

Parameter	Description	Type	Required
type	Blind watermarking type. Valid values: 1 (semi-blind watermarking), 2 (perfectly blind watermarking), 3 (text blind watermarking)	Int	Yes
image	URL of the blind image watermark, which must be URL-safe Base64-encoded. This parameter is required if type is set to 1 or 2, and does not take effect if type is set to 3. The image watermark must: 1. Be stored in the same bucket as the input image. 2. Have a URL that starts with http://. Note that "http://" cannot be omitted or changed to "https://". For example, the following watermark URLs are invalid: examplebucket-1250000000.cos.ap-shanghai.myqcloud.com/watermark.png https://examplebucket-1250000000.cos.ap-shanghai.myqcloud.com/watermark.png	String	No
text	Text watermark, which must be URL-safe Base64-encoded. This parameter is required if type is set to 3 and does not take effect if type is set to 1 or 2.	String	No
level	Perfectly blind watermarking level, which only takes effect when type is set to 2. Valid values: 1 (default), 2, 3. The larger the value, the better the watermarking effects.	Int	No

Request parameters

This API has no request parameter.

Request body

This API does not have a request body.

Response

Response headers

This API only returns Common Response Headers.

Response body

Parameters in the response body are as follows:

Parameter	Description	Type
UploadResult	Upload results	Container

Content of UploadResult:

Parameter	Description	Type
OriginalInfo	Information about the input image	Container
ProcessResults	Processing results	Container

Content of OriginalInfo:

Parameter	Description	Type
Key	Name of the input image	String
location	Location of the input image	String
ImageInfo	Information about the input image	Container

Content of ImageInfo:

Parameter	Description	Type
Format	Image format	String
Width	Image width	Int
Height	Image height	Int
Quality	Image quality	Int
Ave	Image average hue	String
Orientation	Image rotation angle	Int

Content of ProcessResults:

Parameter	Description	Type
Object	Processing results of each image	Container

Content of Object:

Parameter	Description	Type
Key	Filename	String
Location	Image location	String
Format	Image format	String
Width	Image width	Int
Height	Image height	Int
Size	Image size	Int
Quality	Image quality	Int

Example

Request

POST /exampleobject?image_process HTTP/1.1
Host: examplebucket-1250000000.cos.ap-chengdu.myqcloud.com
Date: Tue, 03 Apr 2018 09:06:15 GMT
Authorization:XXXXXXXXXXXX

Pic-Operations:
{
    "is_pic_info": 1,
    "rules": [{
        "fileid": "exampleobject",
        "rule": "watermark/3/type/1/image/aHR0cDovL2V4YW1wbGVzLTEyNTEwMDAwMDQucGljc2gubXlxY2xvdWQuY29tL3NodWl5aW4uanBn"
    }]
}
Content-Length: 64

Response

HTTP/1.1 200 OK
Content-Type: application/xml
Content-Length: 645
Date: Tue, 03 Apr 2018 09:06:16 GMT
Status: 200 OK
x-cos-request-id: NWFjMzQ0MDZfOTBmYTUwXzZkZV8z****

<UploadResult>
          <OriginalInfo>
              <Key>exampleobject</Key>
              <Location>examplebucket-1250000000.cos.ap-chengdu.myqcloud.com/exampleobject</Location>
              <ImageInfo>
                   <Format>JPEG</Format>
                   <Width>640</Width>
                   <Height>427</Height>
                   <Quality>100</Quality>
                   <Ave>0xa18454</Ave>
                   <Orientation>1</Orientation>
              </ImageInfo>
          </OriginalInfo>
          <ProcessResults>
              <Object>
                   <Key>exampleobject</Key>
                   <Location>examplebucket-1250000000.cos.ap-chengdu.myqcloud.com/exampleobject</Location>
                   <Format>png</Format>
                   <Width>640</Width>
                   <Height>427</Height>
                   <Size>463092</Size>
                   <Quality>100</Quality>
              </Object>
          </ProcessResults>
</UploadResult>

Extracting Blind Watermarks

Example 1: Extracting upon upload

Sample request

The request for uploading an image with the blind watermark extracted is the same as that in a PUT Object call, except that you need to add the image processing parameter Pic-Operations to the request header and use the watermark extraction parameter watermark/4.

PUT /<ObjectKey> HTTP/1.1
Host: <BucketName-APPID>.cos.<Region>.myqcloud.com
Date: GMT Date
Authorization:XXXXXXXXXXXX
Pic-Operations: <PicOperations>

[Object Content]

Note：

Authorization: Auth String (See Request Signature for details.)

Request headers

This API uses Common Request Headers.

Add the image processing parameter Pic-Operations (a JSON string) to the request header. Its parameters are as follows:

Parameter	Description	Type	Required
is_pic_info	Whether to return the input image information 0 (default): no 1: yes	Int	No
rules	Processing rules (up to five rules are supported). Each rule corresponds to one processing result. If this parameter is not specified, images will not be processed.	Array	No

Parameters of rules (a JSON array) are as follows:

Parameter	Description	Type	Required
bucket	Name of the destination bucket to store the results, formatted as BucketName-APPID. If this parameter is not specified, the results will be stored in the current bucket.	String	No
fileid	The path and name of the output file The rules for setting this parameter are as follows (assume that the input file is stored in /p1/test1.jpg): 1. A value starting with a slash (/) indicates an absolute path. For example, if fileid is set to /p2/test2.jpg, the test2.jpg file will be stored in the p2 folder. 2. A value not starting with a slash indicates a relative path. For example, if fileid is set to p2/test2.jpg, a folder named p2 is created in the p1 folder, and the test2.jpg file will be stored in the p2 folder. 3. Note: Do not end the value with a slash. Otherwise, an empty filename will be generated.	String	Yes
rule	Processing parameters. For more information, see the image processing API. To process an image using a specified style, the value must start with style/ with the style name followed. For example, if the style name is test, the value of rule should be style/test.	String	Yes

To extract a blind watermark, you need to add the watermark parameter to rule as follows:

watermark/4/type/<type>/image/<imageUrl>

The parameters are as follows:

Parameter	Description	Type	Required
type	Blind watermarking type. Valid values: 1 (semi-blind watermarking), 2 (perfectly blind watermarking), 3 (text blind watermarking). The value must be the same as that used when the blind watermark was added.	Int	Yes
image	Image URL, which should be specified according to the value of type. If the value of type is: 1, image is required and is the URL of the input image. 2, image is required and is the URL of the image watermark. 3, image does not need to be specified and will not take effect. The value of image must be URL-safe Base64-encoded, and the image must: 1. Be stored in the same bucket as the image with the blind watermark. 2. Have a URL that starts with http://. Note that "http://" cannot be omitted or changed to "https://". For example, the following watermark URLs are invalid: examplebucket-1250000000.cos.ap-shanghai.myqcloud.com/watermark.png https://examplebucket-1250000000.cos.ap-shanghai.myqcloud.com/watermark.png	String	No

Request parameters

This API has no request parameter.

Request body

The request body of the API is the binary string of the image.

Response

Response headers

This API only returns Common Response Headers.

Response body

WatermarkStatus will be added to the UploadResult.ProcessResults.Object node only if type is set to 2 in the request body of the blind watermark extraction request.

Parameter	Parent Node	Description	Type
WatermarkStatus	Object	This parameter is returned if type is set to 2 to indicate the confidence of the watermark extracted. Value range: 0–100. If the value is greater than 75, there is a blind watermark. If the value falls in the range of 60−75, there is a suspected blind watermark. If the value is smaller than 60, no blind watermark is extracted.	Int

Example

Request

PUT /exampleobject1 HTTP/1.1
Host: examplebucket-1250000000.cos.ap-chengdu.myqcloud.com
Date: Tue, 03 Apr 2018 09:06:15 GMT
Authorization:XXXXXXXXXXXX

Pic-Operations:
{
    "is_pic_info": 1,
    "rules": [{
        "fileid": "exampleobject2",
        "rule": "watermark/4/type/2/image/aHR0cDovL2V4YW1wbGVzLTEyNTEwMDAwMDQucGljc2gubXlxY2xvdWQuY29tL2ZpbGVuYW1lLmpwZWc="
    }]
}
Content-Length: 64

[Object Content]

Response

HTTP/1.1 200 OK
Content-Type: application/xml
Content-Length: 645
Date: Tue, 03 Apr 2018 09:06:16 GMT
Status: 200 OK
x-cos-request-id: NWFjMzQ0MDZfOTBmYTUwXzZkZV8z****

<UploadResult>
      <OriginalInfo>
          <Key>exampleobject1</Key>
          <Location>examplebucket-1250000000.cos.ap-chengdu.myqcloud.com/exampleobject1</Location>
          <ImageInfo>
                <Format>JPEG</Format>
                <Width>640</Width>
                <Height>427</Height>
                <Quality>100</Quality>
                <Ave>0xa18454</Ave>
                <Orientation>1</Orientation>
                <FrameCount>1</FrameCount>
          </ImageInfo>
      </OriginalInfo>
      <ProcessResults>
          <Object>
                <Key>exampleobject2</Key>
                <Location>examplebucket-1250000000.cos.ap-chengdu.myqcloud.com/exampleobject2</Location>
                <Format>png</Format>
                <Width>640</Width>
                <Height>427</Height>
                <Size>463092</Size>
                <Quality>100</Quality>
                <FrameCount>1</FrameCount>
                <WatermarkStatus>86</WatermarkStatus>
          </Object>
      </ProcessResults>
</UploadResult>

Note：

• If type is set to 1 in the request, imageUrl in rule in Pic-Operations is the URL of the input image without a blind watermark added. If type is set to 2 in the request, imageUrl is the URL of the image watermark.
• url in ProcessResults in the response body is the URL of the image watermark extracted.

Example 2: Extracting from an image stored in COS

The request for extracting a blind watermark from an image stored in COS is the same as that used to Process In-Cloud Data, except that you need to add the image processing parameter Pic-Operations to the request header and use the watermark extraction parameter watermark/4.