Image Thumbs

Easy-to-use library to create image thumbnails from images existing on some (cloud) object storage or from disk.

Works with any storage provider that is supported by object_store.

Supported formats

PNG and JPEG are currently the only supported image formats.

How to use

Sizes

Configure what thumbnails you would like to have in a .yaml file:

thumbs:
  - name: standard      # This name will be added to the thumbnail with an underscore (_)
    # Optional; The default pattern is /{image_stem}_{thumb_name}
    # The original extension is always appended to the end, e.g., `.png`
    naming_pattern: "/{thumb_name}/{image_stem}"
    quality: 80         # PNG ignores this variable as it is always lossless
    size: [ 640, 480 ]  # Target size of the thumbnail. May not always be exact.
    mode: fit           # Available are: 'fit' and 'crop'

  - name: mini
    quality: 80
    size: [ 40, 40 ]
    mode: crop

Google credentials

This crate relies on object_store for the interaction with the storage backend.

To configure the Google Service Account, use one of the following environment variables as described in the object_store crate.

GOOGLE_SERVICE_ACCOUNT: location of service account file
GOOGLE_SERVICE_ACCOUNT_PATH: (alias) location of service account file
SERVICE_ACCOUNT: (alias) location of service account file
GOOGLE_SERVICE_ACCOUNT_KEY: JSON serialized service account key
GOOGLE_BUCKET: bucket name
GOOGLE_BUCKET_NAME: (alias) bucket name

Then use it in your code

use image_thumbs::GoogleCloudStorage;

#[tokio::main]
async fn main() {
    // Path to your thumbnail configuration yaml. You may specify the .yaml extension in the path, but you don't need to.
    let thumbs = image_thumbs::ImageThumbs::<GoogleCloudStorage>::new("examples/image_thumbs")
        .await
        .unwrap();
    thumbs
        .create_thumbs("penguin.jpg", "/thumbs", false)  // do not override existing images
        .await
        .unwrap();
    thumbs
        .create_thumbs("penguin.png", "/thumbs", true)  // do override existing images
        .await
        .unwrap();
}

For AWS S3 the following environment variables as described in the object_store crate:

AWS_BUCKET: required bucket name
AWS_ACCESS_KEY_ID: access_key_id
AWS_SECRET_ACCESS_KEY: secret_access_key
AWS_DEFAULT_REGION: region
AWS_ENDPOINT: endpoint
AWS_SESSION_TOKEN: token
AWS_ALLOW_HTTP: set to "true" to permit HTTP connections without TLS
AWS_REQUEST_PAYER: set to "true" to permit operations on requester-pays buckets.