IMG Processing allows you to apply watermarks to images. This is useful for adding a logo or a text to an image, or for adding a copyright notice.

Despite the name, watermarks are just overlay images that are placed on top of the original image, making more flexible than traditional watermarks.

In this guide, we’ll see how to apply a watermark to an image using the API.

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Uploading our Watermark

The first step is to create our watermark image. For this, we’ll use the upload endpoint.

Upload an Image

Upload an image to the API

First, download the image you want to use as a watermark. Here we’ll use the IMG Processing logo.

Then, copy your api key on the dashboard and replace it on the x-api-key field, and replace the image field with the path to the image you want to use as a watermark.

curl -X POST "https://api.img-processing.com/v1/images" \
     -H "x-api-key: YOUR_API_KEY" \
     -F "image=@logo.png" \
     -F "name=watermark-logo"

This will return an image object with the watermark image.

{
    "id":"image_za9vcdw6yajjyg77v5kkf3bn",
    "name":"watermark-logo",
    "url":null,
    "width":1515,
    "height":1505,
    "format":"png",
    "size":1939304,
    "created_at":"2025-04-01T16:52:32.503Z"
}

Now, we have our watermark image created, and we can apply it to an image.

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Uploading our Image

The next step is to upload the image we want to apply the watermark to. For this, we’ll use the upload endpoint again.

This time, we’ll use the following image:

curl -X POST "https://api.img-processing.com/v1/images" \
     -H "x-api-key: YOUR_API_KEY" \
     -F "image=@cat2.png" \
     -F "name=cat-image"

This will return an image object with the image we want to apply the watermark to.

{
    "id":"image_iv7d1rish0ymrmk7qwuht3ap",
    "name":"cat-image",
    "url":null,
    "width":1024,
    "height":1024,
    "format":"png",
    "size":1427326,
    "created_at":"2025-04-01T16:15:44.212Z"
}

Now, we have our watermark image and our image created, and we can apply the watermark to the image.

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Applying the Watermark

To apply the watermark to the image, we’ll use the watermark endpoint.

Watermark Image

Apply a watermark to an image

As parameters, we need to send the image id of the image we want to apply the watermark to.

https://api.img-processing.com/v1/images/{imageId}/watermark

As body, we need to send the watermark image inside the watermarks array.

{
    "watermarks": [
        {
            "id": "image_za9vcdw6yajjyg77v5kkf3bn",
            "top": 100,
            "left": 100,
            "width": 200,
            "height": 200
        }
    ]
}

Here is an example request:

curl -X POST "https://api.img-processing.com/v1/images/image_iv7d1rish0ymrmk7qwuht3ap/watermark" \
     -H "x-api-key: YOUR_API_KEY" \
     -H "Content-Type: application/json" \
     -d '{
        "watermarks": [
            {
                "id": "image_za9vcdw6yajjyg77v5kkf3bn",
                "top": 100,
                "left": 100,
                "width": 200,
                "height": 200
            }
        ]
    }'

This will return an image object with the watermark applied to the image.

{
    "id":"image_idl1ad5ppzbq65qohwbtcdjc",
    "name":"cat-image",
    "url":null,
    "width":1024,
    "height":1024,
    "format":"png",
    "size":1430284,
    "created_at":"2025-04-01T17:02:58.496Z"
}

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Downloading the Image

Now, we have our image with the watermark applied to it, and we can download it using the download endpoint.

Download an Image

Download an image

 
curl -X GET "https://api.img-processing.com/v1/images/YOUR_IMAGE_ID/download" \
     -H "x-api-key: YOUR_API_KEY" \
     -o "cat-image-removed-background.png"

This will download the image to your computer.

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Try it yourself

You can try this on the Postman collection.

Postman Collection

Try it yourself on the Postman Collection

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Keep Learning

Now that you know how to apply a watermark to an image, you can learn how to do other things with the API.