You can use Jcrop and Carrierwave to crop image. Like this effect
Here is some code https://github.com/luckyyang/imagecrop But it's use Paperclip instand of Carrierwave.
In carriewave, there is some code
version :thumb do
process :crop
resize_to_fill(240, 320)
end
# crop image
def crop
if model.crop_x.present?
resize_to_limit(1280, 1280)
manipulate! do |img|
x = model.crop_x
y = model.crop_y
w = model.crop_w
h = model.crop_h
img.crop("#{w}x#{h}+#{x}+#{y}")
img
end
end
end
I feel apologetic with my bad English. I hope this can help you