Cantaloupe vs PhotoResize Pro

Cantaloupe is a free, open-source, self-hosted image server that creates derivatives from high-resolution sources when requested. It can crop, scale, and rotate images for deep-zoom viewers and on-demand thumbnails, and conforms to every IIIF Image API version through 3.0. Sources may be filesystems, HTTP or HTTPS servers, S3, Azure Storage, or relational database BLOBs. Processing choices include Java 2D, JAI, TurboJPEG, Kakadu, OpenJPEG, Grok, FFmpeg, and PDFBox. Caches can use filesystem, Java heap, JDBC, S3, Azure Storage, or Redis implementations. Security options include selective image and text watermarking, image-region redaction, HTTPS, HTTP Basic authentication, and customizable authorization policies. Configuration uses environment variables or a .properties file, with most changes applying without restart. Java 17 is required at minimum. The project says no official Docker image is currently available.

PhotoResize Pro has no write-up on Specifiction yet; its figures are above.