define default for checkpoint_dir, but allow checkpoint still

ocrd_calamari/ocrd-tool.json

@@ -20,7 +20,7 @@
       "parameters": {
         "checkpoint_dir": {
           "description": "The directory containing calamari model files (*.ckpt.json). Uses all checkpoints in that directory",
-          "type": "string", "format": "file", "cacheable": true
+          "type": "string", "format": "file", "cacheable": true, "default": "qurator-gt4histocr-1.0"
         },
         "checkpoint": {
           "description": "The calamari model files (*.ckpt.json)",

ocrd_calamari/recognize.py

@@ -40,7 +40,7 @@ class CalamariRecognize(Processor):
     def _init_calamari(self):
         os.environ['TF_CPP_MIN_LOG_LEVEL'] = TF_CPP_MIN_LOG_LEVEL
 
-        if self.parameter.get('checkpoint_dir', None):
+        if not self.parameter.get('checkpoint', None) and self.parameter.get('checkpoint_dir', None):
             resolved = self.resolve_resource(self.parameter['checkpoint_dir'])
             self.parameter['checkpoint'] = '%s/*.ckpt.json' % resolved
         checkpoints = glob(self.parameter['checkpoint'])