imwrite saving image file without extension even after specifying the extension.

original= iin;
for hsize=3:2:9
for sigma=0.5:0.5:2
close all;    
file1 =sprintf('Intern_log_plot%d_hsize=%d_sigma=%.1f',n,hsize,sigma);
file2 =sprintf('Intern_log%d_hsize=%d_sigma=%2f',n,hsize,sigma);   
s1=sprintf('%s%s%s%d%s%s',image_folder,l,filenames(n).name,n,l,file1);          
s2=sprintf('%s%s%s%d%s%s',image_folder,l,filenames(n).name,n,l,file2);
h=fspecial('log',hsize,sigma);
pic=imfilter(original,h);                                  
figure;
subplot(2,2,1);
imshow(original);title('Raw Image');
subplot(2,2,2);
imshow(pic);title('Output');
colormap('default');
h=gcf;
saveas(h,s1,'jpg');
imwrite(pic,s2,'jpg');

The imwrite function writes the file to the disk as files without any extension(so the image file is not detected by image viewer softwares), with the format being already specified as 'jpg' in the imwrite function.

Answer 1

[Michael Haderlein]

The file extension will not be added if you already provide a file extension in the filename. As you have dots (.) in your filename, everything after the dot will be seen as a file extension. If you add the file extension in your filename (you can add .jpg in your sprintf formats), it will work.

[YADHUKRISHNAN]

Thanks for the quick reply Michael

[YADHUKRISHNAN]

But the filename does not have an extension specified along with that. I can't add .jpg in sprintf because my filename is dynamic, it changes in each loop and for each images so that I have saved the filename as string

[Michael Haderlein]

Instead of

s1=sprintf('%s%s%s%d%s%s',image_folder,l,filenames(n).name,n,l,file1);

you just use

s1=sprintf('%s%s%s%d%s%s.jpg',image_folder,l,filenames(n).name,n,l,file1);

The same for the other filenames.

[YADHUKRISHNAN]

I need not specify the extension in saveas and imwrite functions. Right?

[YADHUKRISHNAN]

Thanks a lot...The problem got solved.

Answer 2

[YADHUKRISHNAN]

But the filename does not have an extension specified along with that. I can't add .jpg in sprintf because my filename is dynamic, it changes in each loop and for each images so that I have saved the filename as string