Explicit JPEG thumbnail on capture

openflexure_microscope/camera/pi.py

@@ -484,6 +484,7 @@ class PiCameraStreamer(BaseCamera):
         use_video_port: bool = False,
         resize: Tuple[int, int] = None,
         bayer: bool = True,
+        thumbnail: tuple = None
     ):
         """
         Capture a still image to a StreamObject.
@@ -515,6 +516,7 @@ class PiCameraStreamer(BaseCamera):
                 resize=resize,
                 bayer=(not use_video_port) and bayer,
                 use_video_port=use_video_port,
+                thumbnail=thumbnail
             )
 
             # Set resolution and start stream recording if necessary

openflexure_microscope/microscope.py

@@ -384,6 +384,9 @@ class Microscope:
             )
 
             # Capture to output object
+            extras = {}
+            if fmt == "jpeg":
+                extras["thumbnail"] = (200,150,85)
             logging.info("Starting microscope capture %s", output.file)
             self.camera.capture(
                 output,
@@ -391,6 +394,7 @@ class Microscope:
                 resize=resize,
                 bayer=bayer,
                 fmt=fmt,
+                **extras
             )
 
         output.put_and_save(tags, annotations, full_metadata)