Broken download links

[bafonso]

several of the current download links in opencv_extra/testdata/dnn/download_models.py are broken. Not sure dropbox URLS are the most stable or trustworthy...

[berak]

i made a dry run with download_models.py, and indeed, 2 models fail to load (both 302, redirected):

Model <MobileNet-SSD>
  get https://drive.google.com/uc?export=download&id=0B3gersZ2cHIxRm5PMWRoTkdHdHc
  200 OK [0 Mb]

C:\p\ocv\dnn>curl -I "https://drive.google.com/uc?export=download&id=0B3gersZ2cHIxRm5PMWRoTkdHdHc"
HTTP/2 302
content-type: text/html; charset=UTF-8
cache-control: no-cache, no-store, max-age=0, must-revalidate
pragma: no-cache
expires: Mon, 01 Jan 1990 00:00:00 GMT
date: Sat, 23 Feb 2019 09:14:15 GMT
location: https://doc-0g-bs-docs.googleusercontent.com/docs/securesc/ha0ro937gcuc7l7deffksulhg5h7mbp1/6m1324m2eu9j3tn5mp0j557gkoj73o0i/1550908800000/1176983031138940540
9/*/0B3gersZ2cHIxRm5PMWRoTkdHdHc?e=download
...


Model <DenseNet-121>
  get https://drive.google.com/uc?export=download&id=0B7ubpZO7HnlCcHlfNmJkU2VPelE
  200 OK [0 Mb]

C:\p\ocv\dnn>curl -I "https://drive.google.com/uc?export=download&id=0B7ubpZO7HnlCcHlfNmJkU2VPelE"
HTTP/2 302
content-type: text/html; charset=UTF-8
cache-control: no-cache, no-store, max-age=0, must-revalidate
pragma: no-cache
expires: Mon, 01 Jan 1990 00:00:00 GMT
date: Sat, 23 Feb 2019 09:17:24 GMT
location: https://doc-04-44-docs.googleusercontent.com/docs/securesc/ha0ro937gcuc7l7deffksulhg5h7mbp1/h6fmp48l1f5ee5pq01mnos1ndq385hhl/1550908800000/1615455617248797897
1/*/0B7ubpZO7HnlCcHlfNmJkU2VPelE?e=download
...

[dkurt]

Checked it today. Looks like only ONNX models are replaced once again. DenseNet-121 downloaded correctly.

Checksum verification failed for:
* vgg16.tar.gz
* onnx/models/vgg16.onnx
* vgg16-bn.tar.gz
* onnx/models/vgg16-bn.onnx
* resnet18v1.tar.gz
* onnx/models/resnet18v1.onnx
* resnet50v1.tar.gz
* onnx/models/resnet50v1.onnx
* resnet100.tar.gz
* onnx/models/LResNet100E_IR.onnx

[dkurt]

The ONNX nets hashes has been updated with opencv/opencv_extra#599