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Matlab 进阶学习记录

更新时间:2022-08-13 11:56:07

 

最近在看 Faster RCNN的Matlab code,发现很多matlab技巧,活到老,学到老。。。

 

1. conf_proposal  =  proposal_config('image_means', model.mean_image, 'feat_stride', model.feat_stride);

  

function conf = proposal_config(varargin)
% conf = proposal_config(varargin)
% --------------------------------------------------------
% Faster R-CNN
% Copyright (c) 2015, Shaoqing Ren 
% Licensed under The MIT License [see LICENSE for details]
% --------------------------------------------------------
    
    ip = inputParser ;  
    
    %% training
    ip.addParamValue('use_gpu',         gpuDeviceCount > 0, ...            
                                                        @islogical);
                                    
    % whether drop the anchors that has edges outside of the image boundary
    ip.addParamValue('drop_boxes_runoff_image', ...
                                        true,           @islogical);
    
    % Image scales -- the short edge of input image                                                                                                
    ip.addParamValue('scales',          600,            @ismatrix);
    % Max pixel size of a scaled input image
    ip.addParamValue('max_size',        1000,           @isscalar);
    % Images per batch, only supports ims_per_batch = 1 currently
    ip.addParamValue('ims_per_batch',   1,              @isscalar);
    % Minibatch size
    ip.addParamValue('batch_size',      256,            @isscalar);
    % Fraction of minibatch that is foreground labeled (class > 0)
    ip.addParamValue('fg_fraction',     0.5,           @isscalar);
    % weight of background samples, when weight of foreground samples is
    % 1.0
    ip.addParamValue('bg_weight',       1.0,            @isscalar);
    % Overlap threshold for a ROI to be considered foreground (if >= fg_thresh)
    ip.addParamValue('fg_thresh',       0.7,            @isscalar);
    % Overlap threshold for a ROI to be considered background (class = 0 if
    % overlap in [bg_thresh_lo, bg_thresh_hi))
    ip.addParamValue('bg_thresh_hi',    0.3,            @isscalar);
    ip.addParamValue('bg_thresh_lo',    0,              @isscalar);
    % mean image, in RGB order
    ip.addParamValue('image_means',     128,            @ismatrix);
    % Use horizontally-flipped images during training ?
    ip.addParamValue('use_flipped',     true,           @islogical);
    % Stride in input image pixels at ROI pooling level (network specific)
    % 16 is true for {Alex,Caffe}Net, VGG_CNN_M_1024, and VGG16
    ip.addParamValue('feat_stride',     16,             @isscalar);
    % train proposal target only to labled ground-truths or also include
    % other proposal results (selective search, etc.)
    ip.addParamValue('target_only_gt',  true,           @islogical);

    % random seed                    
    ip.addParamValue('rng_seed',        6,              @isscalar);

    
    %% testing
    ip.addParamValue('test_scales',     600,            @isscalar);
    ip.addParamValue('test_max_size',   1000,           @isscalar);
    ip.addParamValue('test_nms',        0.3,            @isscalar);
    ip.addParamValue('test_binary',     false,          @islogical);
    ip.addParamValue('test_min_box_size',16,            @isscalar);
    ip.addParamValue('test_drop_boxes_runoff_image', ...
                                        false,          @islogical);
    
    ip.parse(varargin{:});
    conf = ip.Results;
    
    assert(conf.ims_per_batch == 1, 'currently rpn only supports ims_per_batch == 1');
    
    % if image_means is a file, load it...
    if ischar(conf.image_means)
        s = load(conf.image_means);
        s_fieldnames = fieldnames(s);
        assert(length(s_fieldnames) == 1);
        conf.image_means = s.(s_fieldnames{1});
    end
end

  

The inputParser object allows you to manage inputs to a function by creating an input scheme. To check the input, you can define validation functions for required arguments, optional arguments, and name-value pair arguments. Optionally, you can set properties to adjust the parsing behavior, such as handling case sensitivity, structure array inputs, and inputs that are not in the input scheme.

After calling the parse method to parse the inputs, the inputParser saves names and values of inputs that match the input scheme (stored in Results), names of inputs that are not passed to the function and, therefore, are assigned default values (stored in UsingDefaults), and names and values of inputs that do not match the input scheme (stored in Unmatched).

  

Check the validity of required and optional function inputs.

Create a custom function with required and optional inputs in the file findArea.m.

function a = findArea(width,varargin)
   p = inputParser;
   defaultHeight = 1;
   defaultUnits = 'inches';
   defaultShape = 'rectangle';
   expectedShapes = {'square','rectangle','parallelogram'};

   addRequired(p,'width',@isnumeric);
   addOptional(p,'height',defaultHeight,@isnumeric);
   addParameter(p,'units',defaultUnits);
   addParameter(p,'shape',defaultShape,...
                 @(x) any(validatestring(x,expectedShapes)));

   parse(p,width,varargin{:});
   a = p.Results.width .* p.Results.height;
The input parser checks whether width and height are numeric, and whether the shape matches a string in cell array expectedShapes. @ indicates a function handle, and the syntax @(x) creates an anonymous function with input x. Call the function with inputs that do not match the scheme. For example, specify a nonnumeric value for the width input: findArea('text') Error using findArea (line 14) The value of 'width' is invalid. It must satisfy the function: isnumeric. Specify an unsupported value for shape: findArea(4,'shape','circle') Error using findArea (line 14) The value of 'shape' is invalid. Expected input to match one of these strings: square, rectangle, parallelogram The input, ''circle'', did not match any of the valid strings.

 

 http://www.cnblogs.com/heleifz/p/matlab-function-handle.html 

 

2. assert 语句的使用:

  assert: Generate an error when a condition is violated.  

  assert(EXPRESSION, ERRMSG) evaluates EXPRESSION and, if it is false, displays the string contained in ERRMSG. When ERRMSG is the last input to assert, MATLAB displays it literally, without performing any substitutions on the characters in ERRMSG.

  例如:如果 contion 不成立,则会输出对应的:提示错误信息。

    assert(mod(conf.batch_size, num_images) == 0, ...
        sprintf('num_images %d must divide BATCH_SIZE %d', num_images, conf.batch_size));

  

3.  permute 函数:

 Permute array dimensions.

    B = permute(A,ORDER) rearranges the dimensions of A so that they

    are in the order specified by the vector ORDER.

  

  重新安排矩阵的x,y,z , 在二维中就相当于把x,y 对换,在三维中相当于可以把三个坐标的位置互换。


比如A = 
A(:,:,1)=repmat(1,3,3);
A(:,:,2)=repmat(2,3,3);
A(:,:,3)=repmat(3,3,3);
disp(A);

A(:,:,1) =

     1     1     1
     1     1     1
     1     1     1


A(:,:,2) =

     2     2     2
     2     2     2
     2     2     2


A(:,:,3) =

     3     3     3
     3     3     3
     3     3     3

At = permute(A,[3,2,1]);
disp(At);

At(:,:,1) =

     1     1     1
     2     2     2
     3     3     3


At(:,:,2) =

     1     1     1
     2     2     2
     3     3     3

At(:,:,3) =

     1     1     1
     2     2     2
     3     3     3
permute(A,[3,2,1])

  

4. cellfun 函数:

 

  cellfun: Apply a function to each cell of a cell array. A = cellfun(FUN, C) applies the function specified by FUN to the contents of each cell of cell array C, and returns the results in the array A. 

 

5. 从列表 A 中去搜索列表 B 中是否存在有相交元素,即:求 A and B 的差。

  

select = importdata('/home/wangxiao/Documents/Sun-80-dataset/VGG_16/iter_1/SUN80_50%_selected_without_HD.txt');
Unlabel = importdata('/home/wangxiao/Documents/Sun-80-dataset/iter_1/Sun_100_UnLabel_Train_0.5_.txt');

fid = fopen('/home/wangxiao/Documents/Sun-80-dataset/VGG_16/iter_1/SUN80_50%_Unselected_data.txt', 'a') ;

selected_list = [] ;  
unselected_list = [] ; 

for i = 1:size(Unlabel.data, 1)
    disp(['deal with: ', num2str(i) , '/' , num2str(size(Unlabel.data, 1))]) ;
    unlabel_name = Unlabel.textdata{i, 1};  % Unlabel image name
    unlabel_label = Unlabel.data(i, 1) ;    % Unlabel image label 
    count = 0; 
    for j = 1:size(select.textdata, 1)
        select_name = select.textdata{j, 1};  % selected image name 
        
        if strcmp(unlabel_name, select_name) % if have selected, jump it. 
            selected_list = [selected_list; unlabel_name];
            % break; 
        else
            count = count + 1; 
        end 
        if count == size(select.textdata, 1)
            fprintf(fid, '%s ', num2str(unlabel_name));
            fprintf(fid, '%s \n', num2str(unlabel_label));
        end
    end 
    
end 
 

 

6. containers.Map() 的用法

  matlab中的containers.Map()有点类似于C++ STL中的map容器,具有key/value映射的功能.

    num = containers.Map({1, 2, 3}, {'one', 'two', 'three'})   

  myMap = containers.Map(KEYS, VALUES) constructs a Map object myMap that contains one or more keys and a value for each of these keys, as specified in the KEYS and VALUES arguments. 

  例如:从 Map 上提取一个值:myValue = myMap(key) ;

  修改键值对 (key-values pairs): myMap(key) = newValue ;

  增加一个新的键值对:myMap(key) = newValue ; 

  可以通过 remove 的方法将 values 删除掉。

 

 


7. try catch end 机制:

  该机制可以防止由于程序中可能出现的错误而终止运行的情况:

  try 

   ld     = load(anchor_cache_file) ; 

     anchors   = ld.anchors ; 

  catch 

   base_anchor  = [1, 1, opts.base_size, opts.base_size] ;

     ratio_anchors     = ratio_jitter(base_anchor, opts.ratios) ; 

  end 

 


 8. About change the gray image into 3 channel RGB image: 

 1 clc; close all; clear all;
 2 image = imread('/home/wangxiao/Documents/mnist_dataset/mnist_0_.png');
 3 image = im2double(image);
 4 image = double(image);
 5 width = size(image, 1); height = size(image, 2);
 6 
 7 synthetic = zeros([224, 224]);
 8 
 9 for i = 1:size(image, 1)
10 for j = 1:size(image, 2)
11 
12 synthetic(i, j) = image(i, j); 
13 synthetic(i, j) = image(i, j); 
14 synthetic(i, j) = image(i, j); 
15 end 
16 end 
17 synthetic = im2uint8(synthetic); 
18 imshow(synthetic);
19 figure; imshow(image);
20 
21 %% 
22 synthetic2 = zeros([224, 224, 3]);
23 
24 for i = 1:size(image, 1)
25 for j = 1:size(image, 2)
26 
27 synthetic2(i, j, 1) = image(i, j, 1); 
28 synthetic2(i, j, 2) = image(i, j, 2); 
29 synthetic2(i, j, 3) = image(i, j, 3); 
30 end 
31 end 
32 synthetic2 = im2uint8(synthetic2); 
33 imshow(synthetic2);

 

synthetic is a single channel image, and synthetic2 is a three channel image.  

 

Another Solution is: 

% if grayscale repeat one channel to match filters size
if(size(im, 3)==1)
  im = repmat(im, [1 1 3]);
end


 

9. Divided the image into specific patches using matlab function: mat2cell 

Matlab 进阶学习记录 

  This is a really cool function. For example, you read one image and divide it into 3*3 = 9 patches, and we assume the resolution of the image is: 100*100, you just need set the vectors M = [20, 30, 50]; N = [20, 20, 60] ; 

Actually, as long as the sum of three values you set  equal to 100 (here is 20, 30, 50), it will be ok. The other vector N have the same reason. 

 


 

10. Read images from disks and save these frames into avi video files. 

 

 1 %% change the frame to videos to save. 
 2 clc; close all; clear all; 
 3 path = '/home/wangxiao/Downloads/files/Visual_Tracking/MDNet-CVPR2016/saved_tracking_results_MDNet_OTB100/Biker/';
 4 files = dir([path, '*.png']);
 5 count = 0; 
 6  
 7 for i=1:size(files, 1) 
 8     xxx =  strtok(files(i).name, 'M'); 
 9     name = xxx(7:end-1);
10     image = imread([path, files(i).name]);
11     index = sprintf('%04d', str2double(name));
12     newName = [ index,'.jpg'];
13     
14 %    a = sprintf('%04d',i);
15     
16     imwrite(image, [path, newName]);
17 end
18 
19 disp('==>> deal with image done !')
20  
21  
22 jpgFiles = dir([path, '*.jpg']);
23 videoName = '/home/wangxiao/Videos/Biker_MDNet_OTB100.avi';
24 fps = 25; %帧率
25 startFrame = 1; %从哪一帧开始
26 endFrame = size(jpgFiles, 1); %哪一帧结束
27 
28 %生成视频的参数设定
29 aviobj=VideoWriter(videoName);  %创建一个avi视频文件对象,开始时其为空
30 aviobj.FrameRate=fps;
31 
32 open(aviobj);%Open file for writing video data
33 
34 for i=startFrame:endFrame
35     frames = imread([path, jpgFiles(i).name]); 
36     frames = im2frame(frames); 
37     writeVideo(aviobj, frames); 
38 end
39 close(aviobj); 
40 
41 disp('==>> saved the video !')

 

 

 11.  Matlab中save实现保存数据到mat文件的正确使用  参考:http://blog.csdn.net/fx677588/article/details/52836348 

 1 1. 普通保存在当前文件夹下
 2 
 3   save matPath.mat A B;   % A B都是生成的数据矩阵
 4 
 5   需要注意这种方式只能将数据保存在当前文件夹下的第一个参数文件中,下面这样写并不能将数据保存到你想要的文件夹中的。
 6 
 7   saldir = './result/';
 8   savePath = [saldir imnames(len).name(1:end-4) '_KSD'];
 9   save savePath A;  
10 
11   上面程序也只能实现在当前文件夹下生成savePath.mat文件,然后数据保存到该文件中。并不能保存到需要的文件夹中。正确的写法是下面的方式。
12 
13 2. 保留数据到其他文件夹下
14 
15   saldir = './result/';
16   savePath = [saldir imnames(len).name(1:end-4) '_KSD' '.mat'];
17   save(savePath,'A');  % 保存到其他文件夹的写法
18 
19     这里也需要注意,保存的数据矩阵,即save函数的第二个参数不可以忘记单引号。

 

 12. 根据 attention maps 置信度的高低,生成对应的 bounding box : 

clc;close all;clear all;
Img=imread('/home/wangxiao/Documents/files/Visual_Tracking/MDNet-CVPR2016/MDNet-master/attentionMap/Basketball/0001.png');
if ndims(Img)==3
    I=rgb2gray(Img);
else
    I=Img;
end
I=im2bw(I,graythresh(I));
[m,n]=size(I);
imshow(I);title('binary image');
txt=get(gca,'Title');
set(txt,'fontsize',16);
L=bwlabel(I);
stats=regionprops(L,'all');
set(gcf,'color','w');
set(gca,'units','pixels','Visible','off');
q=get(gca,'position');
q(1)=0;%设置左边距离值为零
q(2)=0;%设置右边距离值为零
set(gca,'position',q);
for i=1:length(stats)
    hold on;
    rectangle('position',stats(i).BoundingBox,'edgecolor','y','linewidth',2);
    temp = stats(i).Centroid;
    plot(temp(1),temp(2),'r.');
    drawnow;
end
frame=getframe(gcf,[0,0,n,m]);
im=frame2im(frame);
imwrite(im,'a.jpg','jpg');%可以修改保存的格式

Matlab 进阶学习记录

 

 13. 将 video 切割为 frame: 

 

%% Input 2 videos and divide it into frames
clc; clear all; close all;
infraredvideo = 'C:\Users\王逍\Desktop\跟踪数据集\videos\';
savePath = 'C:\Users\王逍\Desktop\跟踪数据集\frames\';

% devide the infrared video into infrared images
videoList1=dir(fullfile(infraredvideo,'*.mp4'));
video_num=length(videoList1);

for j=1:video_num
    
    infraredOutPath = [savePath, videoList1(j).name, '\'];
    mkdir(infraredOutPath);
    
    frames = VideoReader([strcat(infraredvideo,videoList1(j).name)]);
    numFrames =frames.NumberOfFrames;
    for k = 1 : numFrames
        disp(['==>> processing video ',num2str(k),' frames, please waiting....']);
        frame = read(frames,k);
        frame = imresize(frame, [480, 640]);
        % figure(1); imshow(frame);
        imwrite(frame, [infraredOutPath, sprintf('%08d.png',k)]);
    end
    
end

 

14. divide the total attention maps according to given video frames such as TC128. 

Matlab 进阶学习记录Matlab 进阶学习记录
 1 %% 
 2 clc; close all; clear all; 
 3 path = '/media/wangxiao/E1F171026416B63F/tracking_benchmark/Temple-color-128/predicted_attentionMaps-v1/';
 4 attentionfiles = dir([path, '*.png']);
 5 
 6 videoPath = '/media/wangxiao/E1F171026416B63F/tracking_benchmark/Temple-color-128/videos/';
 7 videoFiles = dir(videoPath);
 8 videoFiles = videoFiles(3:end); 
 9 total = 0; 
10 savepath = '/media/wangxiao/E1F171026416B63F/tracking_benchmark/Temple-color-128/attentionMaps_per_video-v1/';
11 
12 
13 for i=1:size(videoFiles, 1)
14     numCount = 0; 
15     videoName = videoFiles(i).name; 
16     newVideoPath = [videoPath videoName '/img/'];
17     
18     videoframes = dir([newVideoPath, '*.jpg']);
19 
20     savePath = [savepath videoName '/'];
21     mkdir(savePath);
22     
23     disp(['==>> deal with video file: ', num2str(i)]);
24 %     total = total + size(videoframes, 1); 
25     
26     for j=1:size(videoframes, 1)
27         if numCount < size(videoframes, 1)
28             total = total + 1; 
29             numCount = numCount + 1;
30             img = imread([path attentionfiles(total).name]);
31             % figure(1); imshow(img);
32             
33             temp = sprintf('%04d', numCount); 
34             saveName = [temp '.png'];
35             imwrite(img, [savePath saveName]);
36         else 
37             break; 
38         end
39 
40     
41 
42     end
43 
44 
45 
46 end
47  
View Code

 

15. count the image list into txt files. 

Matlab 进阶学习记录Matlab 进阶学习记录
 1 %%
 2 market1501_path = '/home/wangxiao/Downloads/person-ReID/open-reid/examples/data/market1501/';
 3 txtsavePath = '/home/wangxiao/Downloads/person-ReID/open-reid/examples/data/market1501/image_txt_list/';
 4 
 5 bounding_box_test = [market1501_path 'bounding_box_test/'];
 6 bounding_box_train = [market1501_path 'bounding_box_train/'];
 7 gt_bbox = [market1501_path 'gt_bbox/'];
 8 gt_query = [market1501_path 'gt_query/'];
 9 images = [market1501_path 'images/'];
10 query = [market1501_path 'query/'];
11 
12 
13 % ##################### 
14 bounding_box_test_files = dir([bounding_box_test, '*.jpg']);
15 bounding_box_train_files = dir([bounding_box_train, '*.jpg']);
16 gt_bbox_files = dir([gt_bbox, '*.jpg']);
17 gt_query_files = dir([gt_query, '*.jpg']);
18 images_files = dir([images, '*.jpg']);
19 query_files = dir([query, '*.jpg']);
20 
21 %% image files I 
22 fid = fopen([txtsavePath 'bounding_box_test_files_image_list.txt'], 'w');
23 for i=1:size(bounding_box_test_files, 1)
24     imgName = bounding_box_test_files(i).name;
25     fprintf(fid, '%s \n', imgName);
26 end
27 fclose(fid); 
28 disp('==>> done I'); 
29 
30 %% image files II  
31 fid = fopen([txtsavePath 'bounding_box_train_files_image_list.txt'], 'w');
32 for i=1:size(bounding_box_train_files, 1)
33     imgName = bounding_box_train_files(i).name;
34     fprintf(fid, '%s \n', imgName);
35 end
36 fclose(fid); 
37 disp('==>> done II'); 
38 
39 %% image files III 
40 fid = fopen([txtsavePath 'gt_bbox_files_image_list.txt'], 'w');
41 for i=1:size(gt_bbox_files, 1)
42     imgName = gt_bbox_files(i).name;
43     fprintf(fid, '%s \n', imgName);
44 end
45 fclose(fid); 
46 disp('==>> done III'); 
47 
48 
49 %% image files IV  
50 fid = fopen([txtsavePath 'gt_query_files_image_list.txt'], 'w');
51 for i=1:size(gt_query_files, 1)
52     imgName = gt_query_files(i).name;
53     fprintf(fid, '%s \n', imgName);
54 end
55 fclose(fid); 
56 disp('==>> done IV'); 
57 
58 
59 %% image files V  
60 fid = fopen([txtsavePath 'images_files_image_list.txt'], 'w');
61 for i=1:size(images_files, 1)
62     imgName = images_files(i).name;
63     fprintf(fid, '%s \n', imgName);
64 end
65 fclose(fid); 
66 disp('==>> done V'); 
67 
68 
69 
70 
71 %% image files VI   
72 fid = fopen([txtsavePath 'query_files_image_list.txt'], 'w');
73 for i=1:size(query_files, 1)
74     imgName = query_files(i).name;
75     fprintf(fid, '%s \n', imgName);
76 end
77 fclose(fid); 
78 disp('==>> done VI'); 
View Code

 

16. load json files using matlab code.

  this used package from: http://blog.csdn.net/sophia_xw/article/details/70141208    

  unzip this file and add path to matlab like this: 

  

clear all; clc  
  
addpath('/home/wangxiao/jsonlab-1.5/jsonlab-1.5');
  
fname='results.json';  
jsonData=loadjson(fname);