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Cropping is the removal of unwanted outer areas from a photographic or illustrated image. The process usually consists of the removal of some of the peripheral areas of an image to remove extraneous visual data from the picture, improve itsframing, change theaspect ratio, or accentuate or isolate the subject matter from its background. Depending on the application, this can be performed on a physical photograph, artwork, or film footage, or it can be achieveddigitally by usingimage editingsoftware. The process of cropping is common to thephotographic,film processing,broadcasting,graphic design, andprinting businesses.
In the printing, graphic design and photography industries, cropping is the removal of unwanted areas from the periphery of a photographic or illustratedimage. Cropping is one of the most basicphoto manipulation processes, and it is carried out to remove an unwanted object or irrelevant noise from the periphery of aphotograph, change its aspect ratio, or improve the overallcomposition.
In telephoto photography, most commonly in avian andaviation photography, an image is cropped to magnify the primary subject and further reduce theangle of view. When a lens of sufficient focal length to achieve the desired magnification directly is not available. It is considered one of the few editing actions permissible in modernphotojournalism along with tonal balance, color correction andsharpening. A cropping made by trimming off the top and bottom margins of a photograph, or a film, produces a view that mimics thepanoramic format (in photography) or thewidescreen format incinematography andbroadcasting. Neither of these formats is cropped as such, but rather they are products of highly specialized optical configurations and camera designs.
Cropping in order to emphasize the subject:
Cropping in order to remove unwanted details/objects:
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To assist in precise cropping of a printed image, crop marks may be printed at the four corners of the image, just outside the central area to be retained:⌏ at the top left corner,⌎ at the top right corner,⌍ at the bottom left corner, and⌌ at the bottom right corner. The paper or paperboard on which the image is printed can then be cut on each side so that the crop marks are removed.
In Unicode, the crop marks are represented by:
Crop marks are useful for cropping images printed withbleed, and more generally, when the position of an image on the final sheet is not precisely known in advance.
In certain circumstances, film footage may be cropped to change it from one aspect ratio to another, without stretching the image or filling the blank spaces withletterbox bars (fig. 2).
Concerns about aspect ratios are a major issue infilmmaking. Rather than cropping, the cinematographer usually usesmattes to increase the latitude for alternative aspect ratios in projection and broadcast.Anamorphic optics (such asPanavision lenses) produce afull-frame, horizontally compressed image from which broadcasters and projectionists can matte a number of alternative aspect ratios without cropping relevant image detail. Without this, widescreen reproduction, especially for television broadcasting, is dependent upon a variety of soft matting techniques such as letterboxing, which involves varying degrees of image cropping (see figures 2, 3 and 4).[1]
Since the advent ofwidescreen television, a similar process has removed large chunks from the top & bottom to make a standard 4:3 image fit a 16:9 one, losing 25 percent of the original image. Another option is a process calledpillarboxing, where black bands are placed down the sides of the screen, allowing the original image to be shown full-frame within the wider aspect ratio (fig. 6).
Various methods may be used following cropping or may be used on the original image.
It is not possible to "uncrop" a cropped digital image unless the original still exists or undo information exists: if an image is cropped and saved (without undo information), it cannot be recovered without the original.
However, usingtexture synthesis, it is possible to artificially add a band around an image, synthetically "uncropping" it. This is effective if the band smoothly blends with the existing image, which is relatively easy if the edge of the image has low detail or is a chaotic natural pattern such as sky or grass, but does not work if discernible objects are cut off at the boundary, such as half a car. AnuncropArchived 2010-01-22 at theWayback Machineplug-in exists for theGIMP image editor.
