Allow a default color_formula to be defined on the factory

instead of needing it to be passed through query params.

CHANGES.md

@@ -1,5 +1,10 @@
 # Release Notes
 
+## Next Release
+
+* Allow a default `color_formula` parameter to be set via a dependency (author @samn, https://github.com/developmentseed/titiler/pull/707)
+
+
 ## 0.15.0 (2023-09-28)
 
 ### titiler.core

src/titiler/core/tests/test_factories.py

@@ -1648,3 +1648,34 @@ def test_dst_crs_option():
         )
         meta = parse_img(response.content)
         assert meta["crs"] == CRS.from_epsg(32621)
+
+
+def test_color_formula_dependency():
+    """Ensure that we can set default color formulae via the color_formula_dependency"""
+
+    def custom_color_formula_params() -> Optional[str]:
+        return "sigmoidal R 7 0.4"
+
+    cog = TilerFactory()
+    cog_custom_color_formula = TilerFactory(
+        color_formula_dependency=custom_color_formula_params
+    )
+
+    app = FastAPI()
+    app.include_router(cog.router, prefix="/cog")
+    app.include_router(cog_custom_color_formula.router, prefix="/cog_custom")
+
+    with TestClient(app) as client:
+        response = client.get(
+            f"/cog/tiles/8/87/48.npy?url={DATA_DIR}/cog.tif&color_formula=sigmoidal R 10 0.1"
+        )
+        assert response.status_code == 200
+        assert response.headers["content-type"] == "application/x-binary"
+        npy_tile = numpy.load(BytesIO(response.content))
+        assert npy_tile.shape == (2, 256, 256)  # mask + data
+
+        response = client.get(f"/cog_custom/tiles/8/87/48.npy?url={DATA_DIR}/cog.tif")
+        assert response.status_code == 200
+        assert response.headers["content-type"] == "application/x-binary"
+        numpy.load(BytesIO(response.content))
+        assert npy_tile.shape == (2, 256, 256)  # mask + data

src/titiler/core/titiler/core/factory.py

@@ -146,6 +146,7 @@ class BaseTilerFactory(metaclass=abc.ABCMeta):
     # Image rendering Dependencies
     render_dependency: Type[DefaultDependency] = ImageRenderingParams
     colormap_dependency: Callable[..., Optional[ColorMapType]] = ColorMapParams
+    color_formula_dependency: Callable[..., Optional[str]] = ColorFormulaParams
 
     rescale_dependency: Callable[..., Optional[RescaleType]] = RescalingParams
 
@@ -539,7 +540,7 @@ def tile(
             buffer=Depends(BufferParams),
             post_process=Depends(self.process_dependency),
             rescale=Depends(self.rescale_dependency),
-            color_formula=Depends(ColorFormulaParams),
+            color_formula=Depends(self.color_formula_dependency),
             colormap=Depends(self.colormap_dependency),
             render_params=Depends(self.render_dependency),
             reader_params=Depends(self.reader_dependency),
@@ -625,7 +626,7 @@ def tilejson(
             buffer=Depends(BufferParams),
             post_process=Depends(self.process_dependency),
             rescale=Depends(self.rescale_dependency),
-            color_formula=Depends(ColorFormulaParams),
+            color_formula=Depends(self.color_formula_dependency),
             colormap=Depends(self.colormap_dependency),
             render_params=Depends(self.render_dependency),
             reader_params=Depends(self.reader_dependency),
@@ -705,7 +706,7 @@ def map_viewer(
             buffer=Depends(BufferParams),
             post_process=Depends(self.process_dependency),
             rescale=Depends(self.rescale_dependency),
-            color_formula=Depends(ColorFormulaParams),
+            color_formula=Depends(self.color_formula_dependency),
             colormap=Depends(self.colormap_dependency),
             render_params=Depends(self.render_dependency),
             reader_params=Depends(self.reader_dependency),
@@ -767,7 +768,7 @@ def wmts(
             buffer=Depends(BufferParams),
             post_process=Depends(self.process_dependency),
             rescale=Depends(self.rescale_dependency),
-            color_formula=Depends(ColorFormulaParams),
+            color_formula=Depends(self.color_formula_dependency),
             colormap=Depends(self.colormap_dependency),
             render_params=Depends(self.render_dependency),
             reader_params=Depends(self.reader_dependency),
@@ -898,7 +899,7 @@ def preview(
             image_params=Depends(self.img_preview_dependency),
             post_process=Depends(self.process_dependency),
             rescale=Depends(self.rescale_dependency),
-            color_formula=Depends(ColorFormulaParams),
+            color_formula=Depends(self.color_formula_dependency),
             colormap=Depends(self.colormap_dependency),
             render_params=Depends(self.render_dependency),
             reader_params=Depends(self.reader_dependency),
@@ -965,7 +966,7 @@ def bbox_image(
             image_params=Depends(self.img_part_dependency),
             post_process=Depends(self.process_dependency),
             rescale=Depends(self.rescale_dependency),
-            color_formula=Depends(ColorFormulaParams),
+            color_formula=Depends(self.color_formula_dependency),
             colormap=Depends(self.colormap_dependency),
             render_params=Depends(self.render_dependency),
             reader_params=Depends(self.reader_dependency),
@@ -1028,7 +1029,7 @@ def feature_image(
             image_params=Depends(self.img_part_dependency),
             post_process=Depends(self.process_dependency),
             rescale=Depends(self.rescale_dependency),
-            color_formula=Depends(ColorFormulaParams),
+            color_formula=Depends(self.color_formula_dependency),
             colormap=Depends(self.colormap_dependency),
             render_params=Depends(self.render_dependency),
             reader_params=Depends(self.reader_dependency),

src/titiler/mosaic/titiler/mosaic/factory.py

@@ -24,12 +24,7 @@
 from starlette.responses import HTMLResponse, Response
 from typing_extensions import Annotated
 
-from titiler.core.dependencies import (
-    BufferParams,
-    ColorFormulaParams,
-    CoordCRSParams,
-    DefaultDependency,
-)
+from titiler.core.dependencies import BufferParams, CoordCRSParams, DefaultDependency
 from titiler.core.factory import BaseTilerFactory, img_endpoint_params
 from titiler.core.models.mapbox import TileJSON
 from titiler.core.resources.enums import ImageType, MediaType, OptionalHeader
@@ -274,7 +269,7 @@ def tile(
             buffer=Depends(BufferParams),
             post_process=Depends(self.process_dependency),
             rescale=Depends(self.rescale_dependency),
-            color_formula=Depends(ColorFormulaParams),
+            color_formula=Depends(self.color_formula_dependency),
             colormap=Depends(self.colormap_dependency),
             render_params=Depends(self.render_dependency),
             backend_params=Depends(self.backend_dependency),
@@ -393,7 +388,7 @@ def tilejson(
             buffer=Depends(BufferParams),
             post_process=Depends(self.process_dependency),
             rescale=Depends(self.rescale_dependency),
-            color_formula=Depends(ColorFormulaParams),
+            color_formula=Depends(self.color_formula_dependency),
             colormap=Depends(self.colormap_dependency),
             render_params=Depends(self.render_dependency),
             backend_params=Depends(self.backend_dependency),
@@ -485,7 +480,7 @@ def map_viewer(
             pixel_selection=Depends(self.pixel_selection_dependency),
             buffer=Depends(BufferParams),
             rescale=Depends(self.rescale_dependency),
-            color_formula=Depends(ColorFormulaParams),
+            color_formula=Depends(self.color_formula_dependency),
             colormap=Depends(self.colormap_dependency),
             render_params=Depends(self.render_dependency),
             backend_params=Depends(self.backend_dependency),
@@ -549,7 +544,7 @@ def wmts(
             buffer=Depends(BufferParams),
             post_process=Depends(self.process_dependency),
             rescale=Depends(self.rescale_dependency),
-            color_formula=Depends(ColorFormulaParams),
+            color_formula=Depends(self.color_formula_dependency),
             colormap=Depends(self.colormap_dependency),
             render_params=Depends(self.render_dependency),
             backend_params=Depends(self.backend_dependency),