why images did not save ?

i m saving the following feature extracted image with help of following code

Image </matlabcentral/answers/uploaded_files/7829/h.png>

Code %% Feature Extraction [template mask] = featureext(imP, 1, 18, 1, 0.5); temp{i1}=template;

subplot(pics,columns,subplt);

featureEx=imshow(temp{i1}); filename = sprintf('FeatureExtrctd_image%d.bmp', No_of_images); imwrite(featureEx,filename,'bmp'); title('Feature Extracted image'); subplt=subplt+1; ............ but problem is when i m showing 'FeatureExtrctd_image%d' images it show empty white box why its happening???