New transformation rule may look like (with fixed width of 300, 600, 1700):
{"scheme":null,"host":{"replace":"mediahub.bo.berlin","search":"mediahub.bo.berlin"},"pathQueryFragment":{"replace":"api/File/$1/300.jpg","search":"api/File/Original/([\\-0-9a-f]+)/(.*)"},"mimeType":"image/jpeg","width":300,"height":300,"maxExtend":false}
or for crop
{"scheme":null,"host":{"replace":"pictures.bgbm.org","search":"mediahub.bo.berlin"},"pathQueryFragment":{"replace":"digilib/Scaler/?fn=mediacloud/org1/$1/original/&mo=crop&dw=200&dh=147&uvfix=1","search":"api/File/Original/([\\-0-9a-f]+)/(.*)"},"mimeType":"image/jpeg","width":200,"height":147,"maxExtend":false}
or for flexible width uncroped
{"scheme":null,"host":{"replace":"pictures.bgbm.org","search":"mediahub.bo.berlin"},"pathQueryFragment":{"replace":"digilib/Scaler/IIIF/mediacloud!org1!$1/full/!400,400/0/default.jpg","search":"api/File/Original/([\\-0-9a-f]+)/(.*)"},"mimeType":"image/jpeg","width":400,"height":400,"maxExtend":true}