Why I cannot use Alexnet on my images dataset

2 次查看（过去 30 天）
Hiba Basim Alwan
Hiba Basim Alwan 2018-1-27
回答： Rasaq Kotun 2019-2-12
clc;
clear;
images = imageDatastore('C:\Users\HIBA\Documents\Cancellable Biometrics\Datasets\NIST Faces 1','IncludeSubfolders',true,'LabelSource','foldernames');
[trainingImages,testingImages] = splitEachLabel(images,0.7,'randomized');
net = alexnet;
net.Layers;
layer = 'fc7';
trainingFeatures = activations(net,trainingImages,layer,'outputAs','channels');
testFeatures = activations(net,testingImages,layer);

请先登录，再回答此问题。

回答（3 个）

Walter Roberson
Walter Roberson 2018-1-28
alexnet needs R2016b or later, and requires Neural Network toolbox and requires Neural Network Toolbox Model for AlexNet Network support package
  5 个评论
显示 3更早的评论
Walter Roberson
Walter Roberson 2018-1-28
编辑：Walter Roberson 2018-1-29
One of your images is a different size than the others.
The below code assumes you are using a newer release of MATLAB, which you indicate you are.
projectdir = 'C:\Users\HIBA\Documents\Cancellable Biometrics\Datasets\NIST Faces 1';
dinfo = dir(fullfile(projectdir, '**', '*.*'));
dinfo([dinfo.isdir]) = [];
filenames = fullfile({dinfo.folder}, {dinfo.name});
numfile = length(filenames);
info_struct = struct('filename', '', 'Width', nan, 'Height', nan, 'ColorType', '', 'Message', 'not a valid image file');
image_info(numfile) = info_struct;
info_valid = false(numfile, 1);
for idx = 1 : numfile
thisfile = filenames{idx};
this_info = info_struct;
this_info.filename = thisfile;
try
lastwarn('');
info = imfinfo(thisfile);
msgstr = lastwarn();
if ~isempty(msgstr)
this_info.Message = msgstr;
info_valid(idx) = true;
elseif length(info) == 1
this_info.Message = '';
info_valid(idx) = true;
elseif length(info) > 1
this_info.Message = 'image file with multiple images';
info = info(1);
info_valid(idx) = true;
end
if length(info) == 1
this_info.Width = info.Width;
this_info.Height = info.Height;
this_info.ColorType = info.ColorType;
end
catch ME
end
image_info(idx) = this_info;
end
image_info = image_info(info_valid);
After this, image_info will be a struct with information about all of the image files under the given directory. You can examine, for example
unique([image_info.Width])
unique([image_info.Height])
Sometimes imfinfo produces warnings as it goes: the warnings will be stored in the Message field of the structure. Some image files store multiple images, and in some image file formats those are not guaranteed to be the same size. Only the size information about the first image is returned by the above code, but in such case the Message field is set to 'image file with multiple images'

请先登录，再进行评论。

Rabia Afzal
Rabia Afzal 2018-2-4
i'm also facing the same issue. Can anyone help me in my code?
  2 个评论
Walter Roberson
Walter Roberson 2018-2-6
Start with the code I posted in https://www.mathworks.com/matlabcentral/answers/379353-why-i-cannot-use-alexnet-on-my-images-dataset#comment_529351 but replace projectdir with a character vector that is the top level directory under which all of the images of interest are stored. Run the code and examine the returned information, such as unique([image_info.Width]) to determine what widths actually occur in your files.
Hiba Basim Alwan
Hiba Basim Alwan 2018-2-6
Dear Rabia Afzal
I run the code provided by Walter Roberson and I found that my images is not on the accepted size stated by Alexnet ([227, 227, 3], but in your mind that your images should be color images with three channels). So, I embedded the below code found on Matlab Answers in my program to fix all my images size to 227, 227.
Regards,
images_set.ReadFcn=@(images_set)imresize(imread(images_set),[227 227]);

请先登录，再进行评论。

Rasaq Kotun
Rasaq Kotun 2019-2-12
http://www.bricelam.net/ImageResizer/
i used this and changed the dimensions to 227 x 277 and worked perfectsly

类别

在 Help Center 和 File Exchange 中查找有关 Image Data Workflows 的更多信息

标签

产品

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by