revert 4GRAY

readme.md

@@ -1,6 +1,6 @@
 # rpi-epaper-api
 
-A rest API for setting the display image on a [Waveshare 4.26](https://www.waveshare.com/4.26inch-e-paper-hat.htm) 
+A rest API for setting the display image on a [Waveshare 4.26"](https://www.waveshare.com/4.26inch-e-paper-hat.htm) 
 eink HAT connected to a Raspberry Pi. Supports scaling and rotating the input image. Endpoints are also provided for
 fetching display contents and clearing the display.
 
@@ -37,13 +37,13 @@ curl --form [email protected] --form resize=FIT --form background=WHITE http://r
 
 Data should be sent form-encoded.
 
-| Field        | Description                                                                                                                                                                                                        | Default | Required |
-|--------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------|----------|
-| `image`      | Image file to display. Any image type supported by the Python PIL library should work.                                                                                                                             | N/A     | Yes      |
-| `mode`       | Colour mode used to display the image on the e-ink display.<br>`MONO` - each pixel is either on or off. Uses dithering.<br>`4GRAY` - each pixel is either on, dark gray, light gray or off.                        | MONO    | No       |
-| `resize`     | `FIT` Resize keeping aspect ratio, without cropping<br>`CROP` Resize keeping aspect ratio, with cropping<br>`STRETCH` fill display, ignoring aspect ratio<br>`NONE` Display without any scaling, pixels drawn 1:1. | `FIT`   | No       |
-| `rotate`     | Number of degrees to rotate counter-clockwise, supports increments of 90 degrees.                                                                                                                                  | 0       | No       |
-| `background` | Background colour to use if the image doesn't fill the display. Either `WHITE` or `BLACK`.                                                                                                                         | `WHITE` | No       |
+| Field        | Description                                                                                                                                                                                                                           | Default | Required |
+|--------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------|----------|
+| `image`      | Image file to display. Any image type supported by the Python PIL library should work.                                                                                                                                                | N/A     | Yes      |
+| `mode`       | Display mode, corresponding to the `display_XXX` method on the `epd` object.<br>`FAST` - uses `display_Fast` for a complete screen refresh.<br>`PARTIAL` - uses `display_Partial` for incremental updates (which may cause ghosting). | `FAST`  | No       |
+| `resize`     | `FIT` Resize keeping aspect ratio, without cropping<br>`CROP` Resize keeping aspect ratio, with cropping<br>`STRETCH` fill display, ignoring aspect ratio<br>`NONE` Display without any scaling, pixels drawn 1:1.                    | `FIT`   | No       |
+| `rotate`     | Number of degrees to rotate counter-clockwise, supports increments of 90 degrees.                                                                                                                                                     | 0       | No       |
+| `background` | Background colour to use if the image doesn't fill the display. Either `WHITE` or `BLACK`.                                                                                                                                            | `WHITE` | No       |
 
 Expect this call to take ~4-11 seconds. 
 

src/epd_utils.py

@@ -5,17 +5,24 @@
 from filelock import Timeout as FileLockTimeout, FileLock
 
 from models import Mode
+from sys import path
+
+path.append('lib')
+# noinspection PyUnresolvedReferences
+from waveshare_epd import epd4in26
+
+
+def get_epd():
+    return epd4in26.EPD()
 
 
 def display_clear(epd):
     epd.init()
     epd.Clear()
     epd.sleep()
 
+
 def display_img(epd, image: Image, mode: Mode):
-    if mode == Mode.FOUR_GRAY:
-        epd.init_4GRAY()
-        epd.display_4Gray(epd.getbuffer_4Gray(image))
     if mode == Mode.PARTIAL:
         epd.init()
         for i in range(2):
@@ -25,22 +32,18 @@ def display_img(epd, image: Image, mode: Mode):
         epd.display_Fast(epd.getbuffer(image))
     epd.sleep()
 
+
 def handle_epd_error(e: Exception) -> tuple[Response, int]:
     if isinstance(e, IOError):
         logging.error(f'IOError on display write: {str(e)}')
         return jsonify(message='Unexpected error'), 500
     elif isinstance(e, KeyboardInterrupt):
         logging.info('Display write interrupted due to KeyboardInterrupt')
-        #epd4in26.epdconfig.module_exit(cleanup=True)
+        epd4in26.epdconfig.module_exit(cleanup=True)
         return jsonify(message='Cancelled'), 500
     elif isinstance(e, FileLockTimeout):
         logging.info('Could not obtain device lock')
         return jsonify(message='Device busy, please wait for current request to complete'), 409
     else:
         logging.error(f'Unexpected error occurred - {str(e)}')
         return jsonify(message='Unexpected error occurred'), 500
-
-def get_display_colour_palette() -> list[int]:
-    # https://github.com/waveshareteam/e-Paper/blob/ecdd8cf7bab311e6e290c84c68d474deafb7ca8d/RaspberryPi_JetsonNano/python/lib/waveshare_epd/epd4in26.py#L38
-    colours = [0xff, 0xC0, 0x80, 0x00]
-    return sum([[colour] * 3 for colour in colours], [])

src/img_utils.py

@@ -2,7 +2,6 @@
 from PIL import Image
 
 from models import Resolution, Rotation, Resize, BackgroundColour, Mode
-from epd_utils import get_display_colour_palette
 
 
 def resize_img(img: Image, mode: Mode, rotation: Rotation, resize: Resize, background: BackgroundColour,
@@ -23,18 +22,11 @@ def resize_img(img: Image, mode: Mode, rotation: Rotation, resize: Resize, backg
     scaled_image = out_img.resize(scaled_resolution)
 
     # Add scaled image to full size canvas
-    img_mode = 'RGB' if mode == Mode.FOUR_GRAY else '1'
     bg_colour = 255 if background == BackgroundColour.WHITE else 0
     x = int((display_res.width - scaled_image.width) / 2)
     y = int((display_res.height - scaled_image.height) / 2)
-    canvas = Image.new(img_mode, display_res, bg_colour)
+    canvas = Image.new('1', display_res, bg_colour)
     canvas.paste(scaled_image, (x, y))
-    if mode == Mode.FOUR_GRAY:
-        palette_img = Image.new('P', (16, 16))
-        palette_img.putpalette(get_display_colour_palette() * 32)
-        palette_img.load()
-        canvas = canvas.quantize(palette=palette_img)
-
     return canvas
 
 
@@ -44,5 +36,6 @@ def get_resize_scale(img: Image, crop: bool, display_res: Resolution) -> Tuple[i
     scale = max(width_scale, height_scale) if crop else min(width_scale, height_scale)
     return int(img.width * scale), int(img.height * scale)
 
+
 def image_changed(existing_image: Image, new_image: Image) -> bool:
-    return list(new_image.getdata()) != list(existing_image.getdata())
+    return list(new_image.getdata()) != list(existing_image.getdata())

src/models.py

@@ -24,6 +24,5 @@ class BackgroundColour(StrEnum):
 
 
 class Mode(StrEnum):
-    MONO = 'MONO'
-    FOUR_GRAY = '4GRAY'
+    FAST = 'FAST'
     PARTIAL = 'PARTIAL'

src/server.py

@@ -8,19 +8,14 @@
 from models import Resolution, Rotation, Resize, BackgroundColour, Mode
 
 from img_utils import resize_img, image_changed
-from epd_utils import handle_epd_error, display_clear, display_img
-
-from sys import path
-path.append('lib')
-# noinspection PyUnresolvedReferences
-from waveshare_epd import epd4in26
+from epd_utils import handle_epd_error, display_clear, display_img, get_epd
 
 IMG_PATH = 'img.png'
 DISPLAY_RESOLUTION = Resolution(800, 480)
 
 logging.basicConfig(level=logging.DEBUG)
 
-epd = epd4in26.EPD()
+epd = get_epd()
 
 app = Flask(__name__)
 
@@ -65,7 +60,7 @@ def show_image() -> tuple[Response, int]:
         return jsonify(message=f'"background" invalid, must be one of {", ".join([x for x in BackgroundColour])}'), 422
 
     try:
-        mode = Mode(request.form.get('mode', Mode.MONO.value))
+        mode = Mode(request.form.get('mode', Mode.FAST.value))
     except ValueError:
         return jsonify(message=f'"mode" invalid, must be one of {", ".join([x for x in Mode])}'), 422