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Caffe本身是C++、CUDA语言编写的。在调试模型、参数时,根据运行log、snapshot很难实时反馈当前训练的权值情况,也难以捕捉算法存在的bug。
MATLAB则是非常适合算法设计、快速迭代的利器,只需要做少量工作就能编写出复杂的算法,调试非常方便,位于workspace中的变量随时都能打印,无论是一维、二维还是三维数据,都能直观显示,从而有利于定位算法设计问题,减少调试时间。
Caffe中有两种Wrapper:Python和MATLAB。Python是开源工具,用户无需付费即可使用,缺点是语法不够灵活,尤其算法描述,与商业软件不能比。MATLAB支持几乎你所知道的所有矩阵变换、数值计算、随机过程、概率论、最优化、自适应滤波、图像处理、神经网络等算法。
下面介绍如何用MATLAB调试Caffe。本文假设操作系统为Ubuntu 14.04.1 64bit .
1. 安装MATLAB R2014A
可以到这里下载(,提取码:dxBxMJ)
安装步骤类似Windows,不表。安装到~/MATLAB/,~/.bashrc中添加 export PATH=~/MATLAB/bin:$PATH
2. 安装Caffe
参考步骤:。其他OS请参考。
如果你希望自己编译依赖,可以到这里下载Caffe所有依赖包(,提取码:yuqZm1)
3. 编译 MatCaffe
修改Makefile.config,加上这一句:
MATLAB_DIR := ~/MATLAB
之后
make matcaffe
生成了 matlab/+caffe/private/caffe_.mex64,可以直接被MATLAB调用。
4. 运行MATLAB例子
在命令行中,配置好Caffe运行所需要的环境变量后(否则matcaffe会运行失败),输入matlab&,这样就启动了MATLAB窗口。
在MATLAB命令窗口中进行以下步骤。
>> cd Caffe_root_directory/
切换到了Caffe根目录。
>> addpath('./matlab/+caffe/private');
添加matcaffe模块所在路径到MATLAB搜索路径,便于加载。
>> cd matlab/demo/
切到demo目录。
>> im = imread('../../examples/images/cat.jpg');
读取一张测试图片。
>> figure;imshow(im);
弹出一个窗口,显示猫的测试图片如下:
>> [scores, maxlabel] = classification_demo(im, 1);
Elapsed time is 0.533388 seconds.
Elapsed time is 0.511420 seconds. Cleared 0 solvers and 1 stand-alone nets运行分类demo程序。分类的结果返回到scores,maxlabel两个工作空间变量中。
>> maxlabel
maxlabel = 282说明最大分类概率的标签号为282,查找ImageNet标签,对应的是n02123045 tabby, tabby cat(data/ilsvrc2012/synset_words.txt)
>> figure;plot(scores);
>> axis([0, 999, -0.1, 0.5]);>> grid on
打印scores,一维图像如下:
说明这张图片被分到第282类的概率为0.2985。
到这里我们只是运行了简单的demo,接下来分析classification_demo.m这个文件内容。
function [scores, maxlabel] = classification_demo(im, use_gpu)% [scores, maxlabel] = classification_demo(im, use_gpu)% 使用BVLC CaffeNet进行图像分类的示例% 重要:运行前,应首先从Model Zoo(http://caffe.berkeleyvision.org/model_zoo.html) 下载BVLC CaffeNet训练好的权值%% ****************************************************************************% For detailed documentation and usage on Caffe's Matlab interface, please% refer to Caffe Interface Tutorial at% http://caffe.berkeleyvision.org/tutorial/interfaces.html#matlab% ****************************************************************************%% input% im color image as uint8 HxWx3% use_gpu 1 to use the GPU, 0 to use the CPU%% output% scores 1000-dimensional ILSVRC score vector% maxlabel the label of the highest score%% You may need to do the following before you start matlab:% $ export LD_LIBRARY_PATH=/opt/intel/mkl/lib/intel64:/usr/local/cuda-5.5/lib64% $ export LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libstdc++.so.6% Or the equivalent based on where things are installed on your system%% Usage:% im = imread('../../examples/images/cat.jpg');% scores = classification_demo(im, 1);% [score, class] = max(scores);% Five things to be aware of:% caffe uses row-major order% matlab uses column-major order% caffe uses BGR color channel order% matlab uses RGB color channel order% images need to have the data mean subtracted% Data coming in from matlab needs to be in the order% [width, height, channels, images]% where width is the fastest dimension.% Here is the rough matlab for putting image data into the correct% format in W x H x C with BGR channels:% % permute channels from RGB to BGR% im_data = im(:, :, [3, 2, 1]);% % flip width and height to make width the fastest dimension% im_data = permute(im_data, [2, 1, 3]);% % convert from uint8 to single% im_data = single(im_data);% % reshape to a fixed size (e.g., 227x227).% im_data = imresize(im_data, [IMAGE_DIM IMAGE_DIM], 'bilinear');% % subtract mean_data (already in W x H x C with BGR channels)% im_data = im_data - mean_data;% If you have multiple images, cat them with cat(4, ...)% Add caffe/matlab to you Matlab search PATH to use matcaffeif exist('../+caffe', 'dir') addpath('..');else error('Please run this demo from caffe/matlab/demo');end% Set caffe modeif exist('use_gpu', 'var') && use_gpu caffe.set_mode_gpu(); gpu_id = 0; % we will use the first gpu in this demo caffe.set_device(gpu_id);else caffe.set_mode_cpu();end% Initialize the network using BVLC CaffeNet for image classification% Weights (parameter) file needs to be downloaded from Model Zoo.model_dir = '../../models/bvlc_reference_caffenet/'; % 模型所在目录net_model = [model_dir 'deploy.prototxt']; % 模型描述文件,注意是deploy.prototxt,不包含data layersnet_weights = [model_dir 'bvlc_reference_caffenet.caffemodel']; % 模型权值文件,需要预先下载到这里phase = 'test'; % run with phase test (so that dropout isn't applied) % 只进行分类,不做训练if ~exist(net_weights, 'file') error('Please download CaffeNet from Model Zoo before you run this demo');end% Initialize a networknet = caffe.Net(net_model, net_weights, phase); % 初始化网络if nargin < 1 % For demo purposes we will use the cat image fprintf('using caffe/examples/images/cat.jpg as input image\n'); im = imread('../../examples/images/cat.jpg'); % 获取输入图像end% prepare oversampled input% input_data is Height x Width x Channel x Numtic;input_data = {prepare_image(im)}; % 图像冗余处理toc;% do forward pass to get scores% scores are now Channels x Num, where Channels == 1000tic;% The net forward function. It takes in a cell array of N-D arrays% (where N == 4 here) containing data of input blob(s) and outputs a cell% array containing data from output blob(s)scores = net.forward(input_data); % 分类,得到scorestoc;scores = scores{1};scores = mean(scores, 2); % 取所有分类结果的平均值[~, maxlabel] = max(scores); % 找到最大概率对应的标签号% call caffe.reset_all() to reset caffecaffe.reset_all();% ------------------------------------------------------------------------function crops_data = prepare_image(im)% ------------------------------------------------------------------------% caffe/matlab/+caffe/imagenet/ilsvrc_2012_mean.mat contains mean_data that% is already in W x H x C with BGR channelsd = load('../+caffe/imagenet/ilsvrc_2012_mean.mat');mean_data = d.mean_data;IMAGE_DIM = 256;CROPPED_DIM = 227;% Convert an image returned by Matlab's imread to im_data in caffe's data% format: W x H x C with BGR channelsim_data = im(:, :, [3, 2, 1]); % permute channels from RGB to BGRim_data = permute(im_data, [2, 1, 3]); % flip width and heightim_data = single(im_data); % convert from uint8 to singleim_data = imresize(im_data, [IMAGE_DIM IMAGE_DIM], 'bilinear'); % resize im_dataim_data = im_data - mean_data; % subtract mean_data (already in W x H x C, BGR)% oversample (4 corners, center, and their x-axis flips)crops_data = zeros(CROPPED_DIM, CROPPED_DIM, 3, 10, 'single');indices = [0 IMAGE_DIM-CROPPED_DIM] + 1;n = 1;for i = indices for j = indices crops_data(:, :, :, n) = im_data(i:i+CROPPED_DIM-1, j:j+CROPPED_DIM-1, :); crops_data(:, :, :, n+5) = crops_data(end:-1:1, :, :, n); n = n + 1; endendcenter = floor(indices(2) / 2) + 1;crops_data(:,:,:,5) = ... im_data(center:center+CROPPED_DIM-1,center:center+CROPPED_DIM-1,:);crops_data(:,:,:,10) = crops_data(end:-1:1, :, :, 5);