How to compute volume mean from list? about c3d HOT 4 CLOSED

The command and the input arguments look correct. I think the problem may come from the list file. Some (or at least one) of your input clips (a line in the list file) cannot be read. As shown in your log file, your datum size is 0. But it seems a few clips at the beginning are successfully read. You can check, this is true if you find "Starting Iteration" in your output log.

from c3d.

Hi Du， Thank you for your prompt reply！ I probably found the reason.

The collapse point is at ：

CHECK_EQ(size_in_datum, data_size) << "Incorrect data field size " << size_in_datum;

in compute_volume_mean_from_list.cpp.

When the caffe/util/image_io.cpp read this line:

/media/michael/F/data/UCF-101/UCF-101-frames/v_ApplyEyeMakeup_g09_c04 177 0

with length=16 and sampling_rate=1, image_io.cpp try to read images from 000177.jpg to 000192.jpg, however, v_ApplyEyeMakeup_g01_c04.avi have only 191 frames. So, the ReadImageSequenceToVolumeDatum() will return false. And datum.data().size() is 0;

However, in compute_volume_mean_from_list.cpp, (from Line 88 to 92),

ReadImageSequenceToVolumeDatum(frm_dir.c_str(), start_frm, label, length, height, 
                                     width, sampling_rate, &datum);
const string& data = datum.data();
size_in_datum = datum.data().size(); //
CHECK_EQ(size_in_datum, data_size) << "Incorrect data field size " << size_in_datum;

CHECK_EQ(size_in_datum, data_size) is not passed, because size_in_datum=0.

I try to revise the code：

CHECK_EQ(size_in_datum, data_size) << "Incorrect data field size " << size_in_datum;

into this:

if(size_in_datum !=  data_size) {
      continue;
}

Then it works. But I`m not sure if this is right.

from c3d.

Hi @MichaelXin, your revised code just help you to skip the missing clips, but not solve your problem. I think for computing volume mean, it does not really affect the mean much, e.g. you have many clips and missing some of them does not significantly change the mean. However, you need to fix you list file for later usage (training, fine-tuning).

There is one difference, and I notice that it may be your problem. When you use frames as inputs, frame number starting from 1-n, but if you use video, frame number starting from 0 to (n-1), so caused your problem of missing clips at the end (boundary case).

I am closing this issue for now as the problem comes from the list file.

from c3d.

Thank you for your kind remind! That's really helpful~

from c3d.