IC pipeline to accept PNG images (#870)

* initial commit

* style

Co-authored-by: [email protected] <[email protected]>

Author: dbogunowicz

src/deepsparse/image_classification/pipelines.py

@@ -183,7 +183,7 @@ def _preprocess_image(self, image) -> numpy.ndarray:
             image = Image.fromarray(image)
         elif isinstance(image, str):
             # load image from string filepath
-            image = Image.open(image)
+            image = Image.open(image).convert("RGB")
         elif isinstance(image, numpy.ndarray):
             image = image.astype(numpy.uint8)
             if image.shape[0] < image.shape[-1]: