In computer graphics, image scaling is the process of resizing a digital image. Scaling is a non-trivial process that involves a trade-off between efficiency, smoothness and sharpness. As the size of an image is increased, so the pixels which comprise the image become increasingly visible, making the image appear ‘soft’. Conversely, reducing an image will tend to enhance its smoothness and apparent sharpness. Seam carving (also known as image retargeting, content-aware image resizing, content-aware scaling, liquid resizing, or liquid rescaling), is an algorithm for image resizing, developed by Shai Avidan, of Mitsubishi Electric Research Labs (MERL), and Ariel Shamir, of the Interdisciplinary Center and MERL. It functions by establishing a number of seams (paths of least importance) in an image and automatically removes seams to reduce image size or inserts seams to extend it. The clone tool, as it is known in Adobe Photoshop, GIMP, and Corel PhotoPaint, is used in digital image editing to replace information for one part of a picture with information from another part. In other image editing software, its equivalent is sometimes called a rubber stamp tool or a clone brush. A digital image is a numeric representation of a two-dimensional image. Depending on whether the image resolution is fixed, it may be of vector or raster type. Without qualifications, the term ‘digital image’ usually refers to raster images also called bitmap images. In image processing and image recognition, pixel connectivity is the way in which pixels in 2- or 3-dimensional images relate to their neighbors. In digital imaging, a pixel, or pel, (picture element) is a physical point in a raster image, or the smallest, addressable element in a display device, so it is the smallest, controllable element of a picture represented on the screen. The address of a pixel corresponds to its physical coordinates. LCD pixels are manufactured in a two-dimensional grid, and are often represented using dots or squares, but CRT pixels correspond to their timing mechanisms and sweep rates. Source.