scrapy convert_image - scrapy

Question

I use Scrapy to crawl some images, the images need to cut a part or add water mark. I overwrite the function convert_image in pipelines.py but it didn't work. The code looks like this:
class MyImagesPipeline(ImagesPipeline):
def get_media_requests(self, item, info):
for image_url in item['image_urls']:
yield Request(image_url)
def convert_image(self, image, size=None):
if image.format == 'PNG' and image.mode == 'RGBA':
background = Image.new('RGBA', image.size, (255, 255, 255))
background.paste(image, image)
image = background.convert('RGB')
elif image.mode != 'RGB':
image = image.convert('RGB')
if size:
image = image.copy()
image.thumbnail(size, Image.ANTIALIAS)
else:
# cut water image TODO use defined image replace Not cut
x,y = image.size
if(y>120):
image = image.crop((0,0,x,y-25))
buf = StringIO()
try:
image.save(buf, 'JPEG')
except Exception, ex:
raise ImageException("Cannot process image. Error: %s" % ex)
return image, buf
Any ideas?
UPDATE:
#warwaruk
how have you decided it didn't work? any exception or what? < no exception .I use this code for rewrite function item_completed.and it works good, here is the code:
def item_completed(self, results, item, info):
image_paths = [x['path'] for ok, x in results if ok]
if not image_paths:
raise DropItem("Item contains no images")
if item['refer'] == 'someurl.com' :
for a in image_paths:
o_img = os.path.join(self.store.basedir,a)
if os.path.isfile(o_img):
image = Image.open(o_img)
x,y = image.size
if(y>120):
image = image.crop((0,0,x,y-35))
image.save(o_img,'JPEG');
return item

Answer 1

ImagePipleline convert images to JPEG(RGB mode) automatically, and no “toggler” exists. Although you can modify its implmentaion, it may mess its other logic. So, use MediaPipeline is better -- just download the files.
You can write another application to do post-processing for your image files. It make your logic clear and make scrapy faster.