How to optimize my code ?
8 次查看(过去 30 天)
显示 更早的评论
I am writing a code to read multiple images from a folder which contains multiple sub folders and different type of files. I get a list of all sub folders and look for *.tif images and then analyze them.
Here's the part of code that walks through the folders and reads the image (I found this method under one of the posts in this community) :
start_path = fullfile( 'C:\Project\');
% Get list of all subfolders.
allSubFolders = genpath(start_path);
% Parse into a cell array.
remain = allSubFolders;
listOfFolderNames = {};
while true
[singleSubFolder, remain] = strtok(remain, ';');
if isempty(singleSubFolder)
break;
end
listOfFolderNames = [listOfFolderNames singleSubFolder];
end
numberOfFolders = length(listOfFolderNames);
% Process all image files in those folders.
for k = 1 : numberOfFolders
thisFolder = listOfFolderNames{k};
filePattern = sprintf('%s/*.tif', thisFolder);
baseFileNames = dir(filePattern);
numberOfImageFiles = length(baseFileNames);
% Now we have a list of all files in this folder.
if numberOfImageFiles >= 1
% Go through all those image files.
for f = 1 : numberOfImageFiles
fullFileName = fullfile(thisFolder, baseFileNames(f).name);
% fprintf(' Processing image file %s\n', fullFileName);
I = imread(fullFileName);
%%And Some Analysis..
So the problem is that imread takes too much time. I ran it on sample of about 8000 images and it took 1600 sec(~25min) for the whole code but just imread took about 1100sec. that's a lot of time just to read.
Is this normal with imread or can i try and optimize this. i am only gonna look for *.tif files and if there's a way that i could speed up the reading process, it would be great.
This particular function takes up about 80% of time in imread : " imagesci\private\readtif " and it's child function is : " imagesci\private\rtifc " which takes up 99% of its time.
Any help is appreciated, ThankYou!
4 个评论
回答(1 个)
Walter Roberson
2015-8-6
If you are going to end up reading the same image multiple times (perhaps by running the same program with multiple parameters) then pre-process the images by reading them in and writing them out in binary form.
Depending on how you process the files, you might also find it effective to memory map the binary files into memory when you go to use them. If not then fread() them.
Also, if you have the Parallel Processing Toolbox, you can imread() inside a parfor()
0 个评论
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Image Processing Toolbox 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!