调整大小/裁剪图像编码为base64图像字符串

Question

in my case, there are 2 ways of getting image to resize/crop.

1. upload normal image file
2. giving base64 string data of image

in 1. case, resize and crop is working well:

f = Image.open(uploaded_image)
new_width, new_height = 1200, 630
wpercent = (new_width / float(f.size[0]))
hsize = int((float(f.size[1]) * float(wpercent)))

if f.mode != "RGB":
   f = f.convert('RGB')

og_img = None
if f.size[0] < new_width:
  #upscale
  og_img = f.resize((new_width, hsize), Image.BICUBIC)

elif f.size[0] >= new_width:
  #downscale
  og_img = f.resize((new_width, hsize), Image.ANTIALIAS)

og_img = og_img.crop((0, 0, 1200, 630))

resized/cropped image:

in 2. case, the code is the same as above with slight change in:

base64_image = str(request.POST.get('base64_image')).split(',')[1]
imgfile = open('/'.join([settings.MEDIA_ROOT, 'test.png' ]), 'w+b')
imgfile.write(decodestring(base64_image))
imgfile.seek(0)
f = Image.open(imgfile)

#.. as above

but the resized/cropped image:

why is it in 2.case bad in quality and size? (black bottom part..) what am I doing wrong? am I reading the base64 string in wrong way?

Answer 1

I found a website which has many interesting things in it.It has 2(there are many) tools which maybe can help you.The 1th tool converts image to base64 and the 2th tool minifies the size of image (up to 70% save).

http://www.w3docs.com/tools/minimage/

http://www.w3docs.com/tools/image-base64