WordPress has an inbuilt image cropping mechanism in which every image you upload will generate a series of thumbnails, Mostly these thumbnail sizes are defined in a WordPress theme. The advantage here is the theme will pick up the resized version of the image wherever required (If its defined) hence it improves the speed of the page by serving small and optimized image.
All images you see in you see in the web page is a full scale version and the newly uploaded images are not getting cropped automatically.
You can verify this by checking the uploads folder and see whether prefixed version of the image uploaded is present or not, For example
/wp-content/uploads/2014/05/bg-mountains-60x60.jpg /wp-content/uploads/2014/05/bg-mountains-150x150.jpg /wp-content/uploads/2014/05/bg-mountains-300x124.jpg /wp-content/uploads/2014/05/bg-mountains-300x200.jpg /wp-content/uploads/2014/05/bg-mountains-600x200.jpg /wp-content/uploads/2014/05/bg-mountains-1024x426.jpg /wp-content/uploads/2014/05/bg-mountains.jpg
You can see 6 cropped images of
After carefully examining the folder that the WordPress is not generating cropped images, The only possibility might be that your web host is missing
GD PHP5 library which is used by WordPress to process images. This problem is not so common in shared hosting but its a frequent gotcha moment when setting up a VPS or Dedicated server.
Install Php5 GD Library
In debian based linux flavors you can install it using
sudo apt-get install php5-gd
or install using
yum package manager
sudo yum install php5-gd
Once installed you can verify it by the following command
php5 -i | grep -i --color gd
if you are using
php5-fpm -i | grep -i --color gd
The output should be
/etc/php5/fpm/conf.d/20-gd.ini, gd GD Support => enabled GD Version => 2.0 gd.jpeg_ignore_warning =>; 0 =>; 0
Once you verify that the library is installed and enabled, Try to upload the image again and check for the cropped images in uploads folder.
You may need to regenerate thumbnails, To do so install a plugin called Regenerate Thumbnails and run it by visiting
WP Dashboard >> Tools >> Regenerate Thumbnails. You can even go to
WP Dashboard >> Media and regenerate for individual images.