code: def to_png(frame):
      pil_frame = Image.fromarray(skimage.util.img_as_ubyte(frame))
      pil_frame = pil_frame.convert("RGB")
  
      png_frame = io.BytesIO()
  
      pil_frame.save(png_frame, format="PNG", compress_level=3)
      png_frame.seek(0)
  
      return png_frame.read()
  
file_path: SerpentAI/serpent/frame_transformer.py
imports: import skimage.transform
  import skimage.color
  import skimage.util
  from PIL import Image
  import io
label_desc: Use image node_id 7 for calling the FrameTransformer obj's underlying member method code with example usage: obj.to_png(frame) and returns: png_frame