Add JPEG_QUALITY envvar

README.md

@@ -56,3 +56,10 @@ These tests are dependent on `pytest-docker`, and use the [./tests/docker-compos
 
 OpenAPI docs for the appetiser API can be found at [http://localhost:8000/docs](http://localhost:8000/docs) on a locally running instance of appetiser. These provide documentation and examples for the `convert/` endpoint, along with expected types. 
 
+## Customising
+
+The following environment variables can be used to configure the service
+
+| EnvVar         | Description                                     | Default |
+| -------------- | ----------------------------------------------- | ------- |
+| `JPEG_QUALITY` | Integer, 0-100, controls thumbnail jpeg quality | 90      |

appetiser/convert/config.py

@@ -1,3 +1,4 @@
+from pydantic import conint
 from pydantic_settings import BaseSettings, SettingsConfigDict
 from pathlib import Path
 
@@ -7,4 +8,5 @@ class ConvertConfig(BaseSettings):
     KDU_EXPAND: Path
     KDU_LIB: Path
     OUTPUT_DIR: Path
+    JPEG_QUALITY: conint(ge=0, le=100) = 90
     model_config = SettingsConfigDict(case_sensitive=True)

appetiser/convert/image.py

@@ -8,6 +8,7 @@
 )
 from PIL.Image import Image as PILImage
 
+from .config import ConvertConfig
 from .kdu import IMAGE_MODES
 
 logger = logging.getLogger(__name__)
@@ -278,7 +279,7 @@ def scale_dimensions_to_fit(
 
 
 def resize_and_save_img(
-    img: PILImage, width: int, height: int, dest_path: Path
+    img: PILImage, width: int, height: int, dest_path: Path, config: ConvertConfig
 ) -> PILImage:
     """Resize a PIL Image so that it fits within a square of the provided size,
     and saves this file to the provided dest_path.
@@ -287,6 +288,6 @@ def resize_and_save_img(
     """
     img = img.resize((width, height), resample=Image.LANCZOS)
     logger.debug(f"Image resized: {width=}, {height=})")
-    img.save(dest_path, quality=90)
-    logger.debug(f"Resized image saved to: {dest_path}")
+    img.save(dest_path, quality=config.JPEG_QUALITY)
+    logger.debug(f"Resized image saved to: {dest_path}. Quality: {config.JPEG_QUALITY}")
     return img

appetiser/convert/operations.py

@@ -240,6 +240,7 @@ def create_thumbnails(
             width=calc_thumb_info.width,
             height=calc_thumb_info.height,
             dest_path=calc_thumb_info.path,
+            config=config
         )
         thumbnail_info.append(
             ThumbInfo(

appetiser/main.py

@@ -25,6 +25,8 @@
 def get_convert_config():
     return ConvertConfig()
 
+# call to validate config is correct
+get_convert_config()
 
 @app.get("/ping")
 def ping():