We’re planning on adding this feature in the near future. Once development starts, we’ll update you.
Let me know if you have thoughts or questions. Happy to help!
Laura Wittig, Spark Page Product Manager
Spark Page treats some images in ways that allow them to be fully mobile responsive, and sometimes individual image placement can work differently than some people expect. Right now, the feature is working as expected if you'd like to achieve an effect where an image fills the entire screen. For more information on how Spark Page treats images, please take a look at our help center article: https://adobespark.zendesk.com/hc/en-us/articles/360019941794
As noted in the "Planned Feature" status, we are also planning on releasing a feature that will provide an option to include the whole image in a letterbox for users who do not want any cropping applied to images in fill screen, glideshow backgrounds & split layout backgrounds. For right now, you can utilize the focal point feature to tell us where you'd like to focus your image in fill screen, glideshow backgrounds & split layout backgrounds. We will update this thread when progress is made on that feature.
If this information did not address your question or request, please add a comment and we will do our best to respond.
FOR SPARK POST: This thread is applicable only to Spark Page. If you are referring to image resizing as JPGs or other outputs, you are referring to Spark Post. Please use this forum for Spark Post: https://adobespark.uservoice.com/forums/329007-spark-post-feature-suggestion