gPhoto Python bindings added to improve performance. This allows to show now a preview during countdown.

README.md

@@ -114,13 +114,15 @@ A brief description on how to set-up a Raspberry Pi to use this photobooth softw
    ```
    and run `photobooth.py`
 
-8. Optionally make the software run automatically on startup. To do that, you must simply add a corresponding line in the autostart file of LXDE, which can be found at `~/.config/lxsession/LXDE-pi/autostart`. Assuming you cloned the Photobooth repository into `/home/pi/photobooth`, add the following line into the autostart-file:
+8. Optional but highly recommended, as it improves performance significantly: Download the gPhoto2 Python-bindings [Piggyphoto](https://github.com/alexdu/piggyphoto) and put the folder `piggyphoto` into the Photobooth-directory.
+
+9. Optionally make the software run automatically on startup. To do that, you must simply add a corresponding line in the autostart file of LXDE, which can be found at `~/.config/lxsession/LXDE-pi/autostart`. Assuming you cloned the Photobooth repository into `/home/pi/photobooth`, add the following line into the autostart-file:
    ```
    lxterminal -e "/home/pi/photobooth/photobooth.sh set-time"
    ```
    For this to work you must install `gnome-control-center` by running `sudo apt-get install gnome-control-center` (Unfortunately, this brings along a lot of dependencies - however, I haven't found any lightweight alternative that would allow to simply set date and time using the touch screen).
 
-9. Alternatively, you can also add a Desktop shortcut. Create a file `/home/pi/Desktop/Photobooth.desktop` and enter the following:
+10. Alternatively, you can also add a Desktop shortcut. Create a file `/home/pi/Desktop/Photobooth.desktop` and enter the following:
    ```
    [Desktop Entry]
    Encoding=UTF-8

camera.py

@@ -6,9 +6,17 @@ import subprocess
 try:
     import cv2 as cv
     cv_enabled = True
+    print('OpenCV available')
 except ImportError:
     cv_enabled = False
 
+try:
+    import piggyphoto
+    piggyphoto_enabled = True
+    print('Piggyphoto available')
+except ImportError:
+    piggyphoto_enabled = False
+
 class CameraException(Exception):
     """Custom exception class to handle camera class errors"""
     def __init__(self, message, recoverable=False):
@@ -23,6 +31,12 @@ class Camera_cv:
             self.cap.set(3, picture_size[0])
             self.cap.set(4, picture_size[1])
 
+    def has_preview(self):
+        return True 
+
+    def take_preview(self, filename="/tmp/preview.jpg"):
+        self.take_picture(filename)
+
     def take_picture(self, filename="/tmp/picture.jpg"):
         if cv_enabled:
             r, frame = self.cap.read()
@@ -39,9 +53,15 @@ class Camera_gPhoto:
         self.picture_size = picture_size
         # Print the capabilities of the connected camera
         try:
+            if piggyphoto_enabled:
+                self.cap = piggyphoto.camera()
+                print(self.cap.abilities)
+            else:
                 print(self.call_gphoto("-a", "/dev/null"))
-        except:
+        except CameraException as e:
-            print("Warning: Can't list camera capabilities. Do you have gPhoto2 installed?")
+            print('Warning: Listing camera capabilities failed (' + e.message + ')')
+        except piggyphoto.libgphoto2error as e:
+            print('Warning: Listing camera capabilities failed (' + e.message + ')')
 
     def call_gphoto(self, action, filename):
         # Try to run the command
@@ -61,6 +81,18 @@ class Camera_gPhoto:
                 raise CameraException("Unknown error!\n" + '\n'.join(e.output.split('\n')[1:3]), False)
         return output
 
+    def has_preview(self):
+        return piggyphoto_enabled
+
+    def take_preview(self, filename="/tmp/preview.jpg"):
+        if piggyphoto_enabled:
+            self.cap.capture_preview(filename)	
+        else:
+            raise CameraException("No preview supported!")
+
     def take_picture(self, filename="/tmp/picture.jpg"):
+        if piggyphoto_enabled:
+            self.cap.capture_image(filename)
+        else:
             self.call_gphoto("--capture-image-and-download", filename)
         return filename

gui.py

@@ -53,7 +53,7 @@ class GUI_PyGame:
     def trigger_event(self, event_channel):
         EventModule.post(EventModule.Event(pygame.USEREVENT, channel=event_channel))
 
-    def show_picture(self, filename, size=(0,0), offset=(0,0)):
+    def show_picture(self, filename, size=(0,0), offset=(0,0), flip=False):
         # Use window size if none given
         if size == (0,0):
             size = self.size
@@ -74,6 +74,8 @@ class GUI_PyGame:
         # Create surface and blit the image to it
         surface = pygame.Surface(new_size)
         surface.blit(image, (0,0))
+        if flip:
+            surface = pygame.transform.flip(surface, True, False)
         self.surface_list.append((surface, offset))
 
     def show_message(self, msg, color=(245,245,245), bg=(0,0,0), transparency=True):

photobooth.py

@@ -10,6 +10,7 @@ from time import sleep, clock
 from PIL import Image
 
 from gui import GUI_PyGame as GuiModule
+#from camera import CameraException, Camera_cv as CameraModule
 from camera import CameraException, Camera_gPhoto as CameraModule
 from events import Rpi_GPIO as GPIO
 
@@ -152,7 +153,8 @@ class Photobooth:
             # Do not catch KeyboardInterrupt and SystemExit
             except (KeyboardInterrupt, SystemExit):
                 raise
-            except:
+            except Exception as e:
+                print('SERIOUS ERROR: ' + repr(e))
                 self.handle_exception("SERIOUS ERROR!")
 
     def handle_gpio(self, channel):
@@ -277,6 +279,23 @@ class Photobooth:
         output_image.save(output_filename, "JPEG")
         return output_filename
 
+    def show_counter(self, seconds):
+        if self.camera.has_preview():
+            tic, toc = clock(), 0
+            while toc < self.pose_time:
+                self.display.clear()
+                self.camera.take_preview("/tmp/photobooth_preview.jpg")
+                self.display.show_picture("/tmp/photobooth_preview.jpg", flip=True) 
+                self.display.show_message(str(seconds - int(clock() - tic)))
+                self.display.apply()
+                toc = clock() - tic
+        else:
+            for i in range(seconds):
+                self.display.clear()
+                self.display.show_message(str(seconds - i))
+                self.display.apply()
+                sleep(1)
+
     def take_picture(self):
         """Implements the picture taking routine"""
         # Disable lamp
@@ -286,22 +305,18 @@ class Photobooth:
         self.display.clear()
         self.display.show_message("POSE!\n\nTaking four pictures...");
         self.display.apply()
-        sleep(self.pose_time - 3)
+        sleep(2)
 
         # Extract display and image sizes
         size = self.display.get_size()
         outsize = (int(size[0]/2), int(size[1]/2))
 
-        # Countdown
-        for i in range(3):
-            self.display.clear()
-            self.display.show_message(str(3 - i))
-            self.display.apply()
-            sleep(1)
-
         # Take pictures
         filenames = [i for i in range(4)]
         for x in range(4):
+            # Countdown
+            self.show_counter(self.pose_time)
+
             # Try each picture up to 3 times
             remaining_attempts = 3
             while remaining_attempts > 0:
@@ -329,7 +344,7 @@ class Photobooth:
                     else:
                        raise e
 
-                # Sleep for a little bit if necessary
+                # Measure used time and sleep a second if too fast 
                 toc = clock() - tic
                 if toc < 1.0:
                     sleep(1.0 - toc)