How to solve the problem: Unexpected label ***

[zhangrui0828]

Hi Martin, I found your tutorial very help and I am following it to train a model step by step.
The DeepLab model : DeepLab_LargeFOV.
Dataset: original PASCAL VOC12.
Init model is vgg16_20M.
Solver: exper/voc12/config/DeepLab_LargeFOV/solver_train.prototxt
train_net: exper/voc12/config/DeepLab_LargeFOV/train_train.prototxt
source: exper/voc12/list/train.txt

When I run run_pascal_strong.sh, an error always occur and I can't further proceed. The error is shown below.
…...
I0612 15:44:39.689864 12910 net.cpp:208] This network produces output accuracy
I0612 15:44:39.689891 12910 net.cpp:467] Collecting Learning Rate and Weight Decay.
I0612 15:44:39.689899 12910 net.cpp:219] Network initialization done.
I0612 15:44:39.689903 12910 net.cpp:220] Memory required for data: 3663953152
I0612 15:44:39.689975 12910 solver.cpp:41] Solver scaffolding done.
I0612 15:44:39.689981 12910 solver.cpp:160] Solving DeepLab-LargeFOV
I0612 15:44:39.689985 12910 solver.cpp:161] Learning Rate Policy: step
F0612 15:44:41.198884 12910 softmax_loss_layer.cpp:86] Unexpected label 19
*** Check failure stack trace: ***
@ 0x7efefd561daa (unknown)
@ 0x7efefd561ce4 (unknown)
@ 0x7efefd5616e6 (unknown)
@ 0x7efefd564687 (unknown)
@ 0x5482a8 caffe::SoftmaxWithLossLayer<>::Forward_cpu()
@ 0x47413a caffe::Net<>::ForwardFromTo()
@ 0x4743cf caffe::Net<>::ForwardPrefilled()
@ 0x57a320 caffe::Solver<>::Solve()
@ 0x419be8 train()
@ 0x412278 main
@ 0x7efefa399f45 (unknown)
@ 0x417927 (unknown)
@ (nil) (unknown)
Aborted

The number after “Unpexted label” is always different at every time.
Do you have any ideas on this? That would be really greatful.
Thanks!

[debayan]

Your image needs to be single channel and it should not have a larger number in the pixel value than the number of classes you have specified in your softmax layer.