Method: projects.locations.thumbnails.create

Creates an ID that can be used to render a "thumbnail" image.

This is used in conjunction with GetThumbnailPixels. A call to thumbnails.create provides an expression and some output options. The result of thumbnails.create is an ID that represents an image that is the result of evaluating that expression and applying those options. Subsequently, calls to GetThumbnailPixels can be made to get the image data for the entire resulting image. The ID will be valid for a moderate period (a few hours).

The most common use case for this pair of endpoints is to provide a complex expression via a POST to thumbnails.create, and then fetch the computed image via a GET to GetThumbnailPixels. This two-part process allows for use in more situations than ComputePixels. In particular: - the result of ComputePixels needs to be unwrapped to get the encoded image bytes. The result of GetThumbnailPixels can be displayed directly by a browser. - ComputePixels can only be called by an authorised user, using a properly-scoped OAuth token. thumbnails.create has the same restriction, but GetThumbnailPixels can be invoked with a URL containing an API key, so URLs invoking it can be used more broadly.

The result of evaluating the expression has to meet some reasonable requirements for the requested image format. In particular, JPEG or PNG format requires that there be one or three output bands, and clips values that are outside the 0-255 range.

The description "thumbnail" does not imply a restriction on the size of the computed image: the same restrictions as ComputePixels apply to thumbnails.create/GetThumbnailPixels. Requests are limited to 48MB in uncompressed data per request, computed as the product of the request dimensions in pixels, the number of image bands requested, and the number of bytes per pixel for each band. Requests are also limited to at most 32K pixels in either dimension and at most 1024 bands. Requests exceeding these limits will result in an error code of 400 (BAD_REQUEST).