On the Scenario platform, all images are distributed toward a protected content delivery network. All URLs are signed when you perform GET requests.

💨 Expiration

The signed URLs expire between 7 days and 14 days after the request. As a result, you can easily cache delivered content on the client side: signed URLs don't change for at least 7 days.

🚧

You can't rely on signed url for perpetual content distribution. Either you have to cache them yourselves or request them again.

📐 On-demand resize

The Assets API returns an asset entity with a URL attribute. This attribute is a presigned URL granting access to the asset. You can modify this URL by adding a query string to transform the asset according to your display requirements.

Possible additional query string attributes include:

• width: represents the final asset width is represented in pixels with a numerical value. The default value is auto, which is the only string allowed in this field.
  • auto is used to maintain the original asset ratio when only the height is specified; or to use the default width when both width and height are unspecified.
• height: represents the final asset height is represented in pixels with a numerical value. The default value is auto, which is the only string allowed in this field.
  • auto is used to maintain the original asset ratio when only the width is specified.; or to use the default height when both width and height are unspecified.
• fit: refers to the resize mode used when resizing an image without maintaining its aspect ratio. The allowed values are: (auto, cover, contain, fill, inside, outside). The default value is auto, equivalent to cover for now. But this subject to change in the future.

• format: defines the output format of the asset. Available options include origin, auto, jpeg, png, and webp. Selecting an option other than origin may change the output asset entity's content-type. The default value is origin, which preserves the original asset format. When auto is selected, the best format is determined based on the request's accept-header. Currently, if webp is available, it will be used; otherwise, the original asset's format will be used.
• quality: adjusts the image quality of the encoded output. The allowed values range from 0 to 100, with the default set to 100. Lower quality results in a smaller asset size but with fewer details. A good configuration is having a quality set to 80, which is nearly imperceptible to the human eye but results in an asset that is nearly 2 times smaller.
• rotate: rotates the given asset by any value between 0 and 360 degrees. Please note that if the rotation angle is not a multiple of 90 degrees, the final image may be larger due to inclined content. The default value for the rotation angle is 0.
• blur: adds a Gaussian blur to the asset. Uses an integer value. The default value is 0.
• greyscale: Convert asset in greyscale. Allowed values are true or false. The default value is false.

Usage sample with a given asset's baseUrl, which looks like: https://cdn.scenario.com/assets-transform/assetId?signature=generatedSignatureForAsset&otherSignatureParams=example&…

🚧

Never change the given signature query strings, it would result in an Access Denied Error.

Recommendations

If you are displaying the asset solo or in a grid and you do not need transparency on the asset, make a request with the parameters "format=jpeg&quality=80" at least.

If you know the size of the asset's display, let's suppose the maximum width for this asset at this position is 250px. We recommend setting up the parameter "width=300" in addition to "format=jpeg" and "quality=80".

Examples

Now some examples and the resulting file size:

Going further

In a web browser, you can specify multiple available versions and the browser will automatically select the most appropriate one.

<img src="flower-large.jpg">

<img src="flower-large.jpg" srcset="flower-small.jpg 480w, flower-large.jpg 1080w" sizes="50vw">

More details here.