Gaussian Blurring

Last updated: 2021-10-15 18:05:31

    Overview

    CI uses the imageMogr2 API to blur an image.

    An image can be processed:

    • Upon download
    • Upon upload
    • In cloud

    Restrictions

    • Format: Currently, JPG, BMP, GIF, PNG, and WebP images can be processed, and HEIF images can be decoded and processed.
    • Size: The input image cannot be larger than 32 MB, with its width and height not exceeding 30,000 pixels, and the total number of pixels not exceeding 250 million. The width and height of the output image cannot exceed 9,999 pixels. For an input animated image, the total number of pixels (Width x Height x Number of frames) cannot exceed 250 million pixels.
    • Number of frames (for animated images): For GIF, the number of frames cannot exceed 300.

    API Format

    1. Processing upon download

    download_url?imageMogr2/blur/<radius>x<sigma>                            
    

    2. Processing upon upload

    PUT /<ObjectKey> HTTP/1.1
    Host: <BucketName-APPID>.cos.<Region>.myqcloud.com
    Date: GMT Date
    Authorization: Auth String
    Pic-Operations: 
    {
    "is_pic_info": 1,
    "rules": [{
        "fileid": "exampleobject",
        "rule": "imageMogr2/blur/<radius>x<sigma>"
    }]
    }
    

    3. Processing in-cloud data

    POST /<ObjectKey>?image_process HTTP/1.1
    Host: <BucketName-APPID>.cos.<Region>.myqcloud.com
    Date: GMT Date
    Content-length: Size
    Authorization: Auth String
    Pic-Operations: 
    {
    "is_pic_info": 1,
    "rules": [{
        "fileid": "exampleobject",
        "rule": "imageMogr2/blur/<radius>x<sigma>"
    }]
    }
    
    Note:

    Authorization: Auth String (For more information, please see Request Signature.)

    Parameters

    Operation: blur

    Parameter Description
    download_url URL of the input image, formatted as &amp;dxlt;BucketName-APPID>.cos.&amp;dxlt;Region>.myqcloud.com/&amp;dxlt;picture name>
    Example: examplebucket-1250000000.cos.ap-shanghai.myqcloud.com/picture.jpeg
    radius&dxlt;radius> Blurring radius. Value range: 1 - 50.
    sigma&dxlt;sigma> Standard deviation of normal distribution. The value must be greater than 0.
    /ignore-error/1 If this parameter is carried and the image failed to be processed because it is too large, the input image will be returned with no error reported.

    Examples

    Note:

    Processing upon download is used as an example here, which does not store the output image in a bucket. If you need to store the output image, please see Persistent Image Processing and use Processing upon upload or Processing in-cloud data.

    Example 1: blurring an image with a radius of 8 and the sigma 5

    http://examples-1251000004.cos.ap-shanghai.myqcloud.com/sample.jpeg?imageMogr2/blur/8x5
    

    Output image:

    Example 2: blurring an image with a radius of 8 and the sigma 5 with a signature carried

    This example processes the image in the same way as in the example above except that a signature is added. The signature is joined with other processing parameters using an ampersand (&):

    http://examples-1251000004.cos.ap-shanghai.myqcloud.com/sample.jpeg?q-sign-algorithm=<signature>&imageMogr2/blur/8x5
    
    Note:

    You can obtain the value of <signature> by referring to Request Signature.

    Notes

    To prevent unauthorized users from accessing or downloading the input image by using a URL that does not contain any processing parameter, you can add the processing parameters to the request signature, making the processing parameters the key of the parameter with the value left empty. The following is a simple example for your reference (it might have expired or become inaccessible). For more information, please see Request Signature.

    http://examples-1251000004.cos.ap-shanghai.myqcloud.com/sample.jpeg?q-sign-algorithm=sha1&q-ak=AKID********************&q-sign-time=1593342360;1593342720&q-key-time=1593342360;1593342720&q-header-list=&q-url-param-list=watermark%252f1%252fimage%252fahr0cdovl2v4yw1wbgvzlteyntewmdawmdqucgljc2gubxlxy2xvdwquy29tl3nodwl5aw4uanbn%252fgravity%252fsoutheast&q-signature=26a429871963375c88081ef60247c5746e834a98&watermark/1/image/aHR0cDovL2V4YW1wbGVzLTEyNTEwMDAwMDQucGljc2gubXlxY2xvdWQuY29tL3NodWl5aW4uanBn/gravity/southeast