diff --git a/common/common/images.py b/common/common/images.py new file mode 100644 index 0000000..5cf5471 --- /dev/null +++ b/common/common/images.py @@ -0,0 +1,46 @@ + +import os +from io import BytesIO + +from PIL import Image + +# The region of the frame image to place on the template. +# Format is (top_left_x, top_left_y, bottom_right_x, bottom_right_y). +# The frame is scaled to the size of the template before this is done. +FRAME_CROP = None # no crop + +# The location in the template to place the frame image after cropping. +# Format is (x, y) of top-left corner. +FRAME_LOCATION = (0, 90) + + +def compose_thumbnail_template(base_dir, template_name, frame_data): + template_path = os.path.join(base_dir, "thumbnail_templates", f"{template_name}.png") + template = Image.open(template_path) + # PIL can't load an image from a byte string directly, we have to pretend to be a file + frame = Image.open(BytesIO(frame_data)) + + # The parameters of how we overlay the template are hard-coded for now. + # We can make this configurable later if needed. + + # Create a new blank image of the same size as the template + result = Image.new('RGBA', template.size) + # If the frame is not the same size, scale it so it is. + # For choice of rescaling filter, pick LANCZOS (aka. ANTIALIAS) as it is highest quality + # and we don't really care about performance. + if frame.size != template.size: + frame = frame.resize(template.size, Image.LANCZOS) + # Insert the frame at the desired location and cropping + if FRAME_CROP is not None: + frame = frame.crop(FRAME_CROP) + result.paste(frame, FRAME_LOCATION) + # Place the template "on top", letting the frame be seen only where the template's alpha + # lets it through. + result.alpha_composite(template) + + buf = BytesIO() + # PIL can't save an image to a byte string directly, we have to pretend to write it to + # a file, rewind the file, then read it again. + result.save(buf, format='png') + buf.seek(0) + return buf.read() diff --git a/cutter/setup.py b/cutter/setup.py index 0483c07..62b3a1b 100644 --- a/cutter/setup.py +++ b/cutter/setup.py @@ -7,6 +7,7 @@ setup( install_requires = [ "argh", "gevent", + "Pillow", # for thumbnail templating "prometheus-client", "psycogreen", "psycopg2",