Before we start: do not forget include CarrierWave::MiniMagick line for this methods.
Using: process :resize_to_fill => [200, 150]
Selected rectangle will be fully filled by image. If system will need, image will be resized and croped.
One side using: process :resize_to_fill => [200, 0]
Using: process :resize_to_fit => [400, 400]
Image will be fit for selected rectangle: will be resized for touching closer side of rectangle, but not croped;
One side using: process :resize_to_fit => [400, nil]
Using: process :resize_to_limit => [260, 340]
Works like "resize_to_fit", but image can resize only to smaller size (save quality mode).
One side using: process :resize_to_limit => [260, nil]
