cleanup and files added

qt_app_pyside1/vlm_backend/utils.py

@@ -0,0 +1,126 @@
+# Copyright 2018-2021 Streamlit Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import imghdr
+import io
+import mimetypes
+from typing import cast
+from urllib.parse import urlparse
+
+import numpy as np
+from PIL import Image, ImageFile
+import hashlib
+import base64
+
+# Maximum content width
+MAXIMUM_CONTENT_WIDTH = 1460  # 2 * 730
+
+def _image_has_alpha_channel(image):
+    """Check if the image has an alpha channel."""
+    if image.mode in ("RGBA", "LA") or (
+        image.mode == "P" and "transparency" in image.info
+    ):
+        return True
+    else:
+        return False
+
+def _format_from_image_type(image, output_format):
+    """Determine the output format based on image type."""
+    output_format = output_format.upper()
+    if output_format == "JPEG" or output_format == "PNG":
+        return output_format
+
+    # We are forgiving on the spelling of JPEG
+    if output_format == "JPG":
+        return "JPEG"
+
+    if _image_has_alpha_channel(image):
+        return "PNG"
+
+    return "JPEG"
+
+def _PIL_to_bytes(image, format="JPEG", quality=100):
+    """Convert PIL image to bytes."""
+    tmp = io.BytesIO()
+
+    # User must have specified JPEG, so we must convert it
+    if format == "JPEG" and _image_has_alpha_channel(image):
+        image = image.convert("RGB")
+
+    image.save(tmp, format=format, quality=quality)
+
+    return tmp.getvalue()
+
+def _BytesIO_to_bytes(data):
+    """Convert BytesIO to bytes."""
+    data.seek(0)
+    return data.getvalue()
+
+def _normalize_to_bytes(data, width, output_format):
+    """Normalize image data to bytes with proper format and size."""
+    image = Image.open(io.BytesIO(data))
+    actual_width, actual_height = image.size
+    format = _format_from_image_type(image, output_format)
+    if output_format.lower() == "auto":
+        ext = imghdr.what(None, data)
+        mimetype = mimetypes.guess_type("image.%s" % ext)[0]
+    else:
+        mimetype = "image/" + format.lower()
+
+    if width < 0 and actual_width > MAXIMUM_CONTENT_WIDTH:
+        width = MAXIMUM_CONTENT_WIDTH
+
+    if width > 0 and actual_width > width:
+        new_height = int(1.0 * actual_height * width / actual_width)
+        image = image.resize((width, new_height), resample=Image.BILINEAR)
+        data = _PIL_to_bytes(image, format=format, quality=90)
+        mimetype = "image/" + format.lower()
+
+    return data, mimetype
+
+def generate_image_hash(image, mimetype):
+    """Generate a SHA-224 hash for an image."""
+    hasher = hashlib.sha224()
+    hasher.update(image)
+    hasher.update(mimetype.encode())
+    return hasher.hexdigest()
+
+def image_to_url(image, width=-1, output_format="auto"):
+    """
+    Convert an image to a data URL.
+    
+    Args:
+        image: The image data
+        width: Target width (negative means preserve original if under max width)
+        output_format: Output format (auto, jpeg, png)
+        
+    Returns:
+        Data URL of the image
+    """
+    image_data, mimetype = _normalize_to_bytes(image, width, output_format)
+    image_base64 = base64.b64encode(image_data).decode("utf-8")
+    return f"data:{mimetype};base64,{image_base64}"
+
+def video_to_url(video_data):
+    """
+    Convert video data to a data URL.
+    
+    Args:
+        video_data: The video data
+        
+    Returns:
+        Data URL of the video
+    """
+    video_base64 = base64.b64encode(video_data).decode("utf-8")
+    return f"data:video/mp4;base64,{video_base64}"