Things you might not expect as default behaviors when using Blitline, so please keep the following in mind:
- Files with a rotation flag set will automatically be rotated into the proper orientation. (You can change this by setting suppress_auto_orient to true.)
- Files output by Blitline are optimized for size, so default images have a .jpg quality of 80 (You can change this with the “quality” setting. See above.)
- Files output by Blitline are optimized for size, so they will have all metadata (EXIF, Color Profiles, etc.) stripped from them. (You can override this by setting “save_metadata” to true. See above.)
- Jobs with a postback will NOT be put into the polling cache, so you can have one or the other, but not both.
- Files uploaded to S3 will, by default, have their permissions set to publicly viewable. You can change this by setting the headers in the “s3_destination” field
- All color profiles are DELETED by default. Only if you set save_profiles:true or save_metadata:true or v:1.20 (or greater) will your embedded color information be preserved.
- Resizing functions, such as resize_to_fit and resize_to_fill will SCALE UP images be default. You must have a only_shrink_larger : true if you want images to remain the same size if their beginning dimensions are less then the desired height/width.
S3 has a latency between when the file completes uploading and when it’s available via it’s url. This mostly is milliseconds, but it can be upwards of 1+ seconds. Blitline has an option of wait_fo_s3 which will cause Blitline to confirm the url is avialable before issuing a postback to you.
(According to AWS, this is no longer true. S3 is read-after-write consistent for all bucket regions)