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Cropping (image)
Encyclopedia
Cropping refers to the removal of the outer parts of an image to improve framing, accentuate subject matter or change aspect ratio
. Depending on the application, this may be performed on a physical photograph, artwork or film footage, or achieved digitally
using image editing
software. The term is common to the film
, broadcasting
, photographic
, graphic design
and printing
industries.
In the printing, graphic design and photography industries, cropping refers to removing unwanted areas from a photographic or illustrated image
. One of the most basic photo manipulation
processes, it is performed in order to remove an unwanted subject or irrelevant detail from a photo, change its aspect ratio, or to improve the overall composition
. In telephoto photography, most commonly in bird photography, an image is cropped to magnify the primary subject and further reduce the angle 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 modern photojournalism
along with tonal balance, colour correction and sharpening
. A crop made from the top and bottom of a photograph may produce an aspect which mimics the panoramic
format (in photography) and the widescreen
format in cinematography
and broadcasting
. Both of these formats are not cropped as such, rather the product of highly specialised optical configuration and camera design.
Cropping in order to remove unwanted details\objects:
bars (fig. 2).
Aspect ratio concerns are a major issue in film making. Rather than cropping, the cinematographer traditionally uses matte
s to increase the latitude for alternative aspect ratios in projection and broadcast. Anamorphic
optics (such as Panavision
lenses) produce a full-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 http://www.filmbug.com/dictionary/aspect-ratios.php(see figures 2, 3 and 4)
Since the advent of widescreen
television, a similar process removes large chunks from the top & bottom to make a standard 4:3 image fit a 16:9 one, losing 25% of the original image. This process has become standard in the United Kingdom , in TV shows where many archive clips are used, which gives them a zoomed-in, cramped image with significantly reduced resolution. This is nonetheless preferred to a process called pillarboxing, where black bands are placed down the sides of the screen, allowing the origial image to be shown full-frame within the wider aspect ratio (fig. 6). See this article for a fuller description of the problem.
File:Image cropping aspect ratios.jpg|Figure 1:
2.35:1 original image with widescreen aspect ratio, showing alternative aspect ratios
File:Image cropping 235x1.jpg|Figure 2:
2.35:1 image with letterbox resized to 4:3, the whole image is visible
File:Image cropping 185x1.jpg|Figure 3:
1.85:1 image with letterbox resized to 4:3. Typical 16:9 image, the outer edges of the image are not visible
File:Image cropping 155x1.jpg|Figure 4:
1.55:1 image with letterbox resized to 4:3. A compromise between 16:9 and 4:3, often broadcast in the UK
File:Image cropping 133x1.jpg|Figure 5:
1.33:1 image without letterbox, because it is cropped to 4:3, losing much of the original
However, using texture 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. An uncrop plug-in exists for the GIMP
image editor.
Aspect ratio
The aspect ratio of a shape is the ratio of its longer dimension to its shorter dimension. It may be applied to two characteristic dimensions of a three-dimensional shape, such as the ratio of the longest and shortest axis, or for symmetrical objects that are described by just two measurements,...
. Depending on the application, this may be performed on a physical photograph, artwork or film footage, or achieved digitally
Workstation
A workstation is a high-end microcomputer designed for technical or scientific applications. Intended primarily to be used by one person at a time, they are commonly connected to a local area network and run multi-user operating systems...
using image editing
Image editing
Image editing encompasses the processes of altering images, whether they be digital photographs, traditional analog photographs, or illustrations. Traditional analog image editing is known as photo retouching, using tools such as an airbrush to modify photographs, or editing illustrations with any...
software. The term is common to the film
Film
A film, also called a movie or motion picture, is a series of still or moving images. It is produced by recording photographic images with cameras, or by creating images using animation techniques or visual effects...
, broadcasting
Broadcasting
Broadcasting is the distribution of audio and video content to a dispersed audience via any audio visual medium. Receiving parties may include the general public or a relatively large subset of thereof...
, photographic
Photography
Photography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...
, graphic design
Graphic design
Graphic design is a creative process – most often involving a client and a designer and usually completed in conjunction with producers of form – undertaken in order to convey a specific message to a targeted audience...
and printing
Offset printing
Offset printing is a commonly used printing technique in which the inked image is transferred from a plate to a rubber blanket, then to the printing surface...
industries.
Cropping in photography, print & design
Image
An image is an artifact, for example a two-dimensional picture, that has a similar appearance to some subject—usually a physical object or a person.-Characteristics:...
. One of the most basic photo manipulation
Photo manipulation
Photo manipulation is the application of image editing techniques to photographs in order to create an illusion or deception , through analog or digital means.- Types of digital photo manipulation :...
processes, it is performed in order to remove an unwanted subject or irrelevant detail from a photo, change its aspect ratio, or to improve the overall composition
Composition (visual arts)
In the visual arts – in particular painting, graphic design, photography and sculpture – composition is the placement or arrangement of visual elements or ingredients in a work of art or a photograph, as distinct from the subject of a work...
. In telephoto photography, most commonly in bird photography, an image is cropped to magnify the primary subject and further reduce the angle 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 modern photojournalism
Photojournalism
Photojournalism is a particular form of journalism that creates images in order to tell a news story. It is now usually understood to refer only to still images, but in some cases the term also refers to video used in broadcast journalism...
along with tonal balance, colour correction and sharpening
Unsharp masking
Unsharp masking is an image manipulation technique, often available in digital image processing software.The "unsharp" of the name derives from the fact that the technique uses a blurred, or "unsharp," positive to create a "mask" of the original image...
. A crop made from the top and bottom of a photograph may produce an aspect which mimics the panoramic
Panoramic photography
Panoramic photography is a technique of photography, using specialized equipment or software, that captures images with elongated fields of view. It is sometimes known as wide format photography. The term has also been applied to a photograph that is cropped to a relatively wide aspect ratio...
format (in photography) and the widescreen
Widescreen
Widescreen images are a variety of aspect ratios used in film, television and computer screens. In film, a widescreen film is any film image with a width-to-height aspect ratio greater than the standard 1.37:1 Academy aspect ratio provided by 35mm film....
format in cinematography
Cinematography
Cinematography is the making of lighting and camera choices when recording photographic images for cinema. It is closely related to the art of still photography...
and broadcasting
Broadcasting
Broadcasting is the distribution of audio and video content to a dispersed audience via any audio visual medium. Receiving parties may include the general public or a relatively large subset of thereof...
. Both of these formats are not cropped as such, rather the product of highly specialised optical configuration and camera design.
Graphic examples (photography)
Cropping in order to emphasize the subject:Cropping in order to remove unwanted details\objects:
Cropping in cinematography & broadcasting
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 with letterboxLetterbox
Letterboxing is the practice of transferring film shot in a widescreen aspect ratio to standard-width video formats while preserving the film's original aspect ratio. The resulting videographic image has mattes above and below it; these mattes are part of the image...
bars (fig. 2).
Aspect ratio concerns are a major issue in film making. Rather than cropping, the cinematographer traditionally uses matte
Matte
Matte may refer to:In film:* Matte , filmmaking and video production technology* Matte painting, a process of creating sets used in film and video* Matte box, a camera accessory for controlling lens glare...
s to increase the latitude for alternative aspect ratios in projection and broadcast. Anamorphic
Anamorphic format
Anamorphic format is a term that can be used either for: the cinematography technique of capturing a widescreen picture on standard 35 mm film, or other visual recording media, with a non-widescreen native aspect ratio; or a photographic projection format in which the original image requires an...
optics (such as Panavision
Panavision
Panavision is an American motion picture equipment company specializing in cameras and lenses, based in Woodland Hills, California. Formed by Robert Gottschalk as a small partnership to create anamorphic projection lenses during the widescreen boom in the 1950s, Panavision expanded its product...
lenses) produce a full-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 http://www.filmbug.com/dictionary/aspect-ratios.php(see figures 2, 3 and 4)
Since the advent of widescreen
Widescreen
Widescreen images are a variety of aspect ratios used in film, television and computer screens. In film, a widescreen film is any film image with a width-to-height aspect ratio greater than the standard 1.37:1 Academy aspect ratio provided by 35mm film....
television, a similar process removes large chunks from the top & bottom to make a standard 4:3 image fit a 16:9 one, losing 25% of the original image. This process has become standard in the United Kingdom , in TV shows where many archive clips are used, which gives them a zoomed-in, cramped image with significantly reduced resolution. This is nonetheless preferred to a process called pillarboxing, where black bands are placed down the sides of the screen, allowing the origial image to be shown full-frame within the wider aspect ratio (fig. 6). See this article for a fuller description of the problem.
File:Image cropping aspect ratios.jpg|Figure 1:
2.35:1 original image with widescreen aspect ratio, showing alternative aspect ratios
File:Image cropping 235x1.jpg|Figure 2:
2.35:1 image with letterbox resized to 4:3, the whole image is visible
File:Image cropping 185x1.jpg|Figure 3:
1.85:1 image with letterbox resized to 4:3. Typical 16:9 image, the outer edges of the image are not visible
File:Image cropping 155x1.jpg|Figure 4:
1.55:1 image with letterbox resized to 4:3. A compromise between 16:9 and 4:3, often broadcast in the UK
File:Image cropping 133x1.jpg|Figure 5:
1.33:1 image without letterbox, because it is cropped to 4:3, losing much of the original
Additional methods
Various methods may be used following cropping or may be used on the original image.- VignettingVignettingIn photography and optics, vignetting is a reduction of an image's brightness or saturation at the periphery compared to the image center. The word vignette, from the same root as vine, originally referred to a decorative border in a book. Later, the word came to be used for a photographic...
is the accentuation of the central portion of an image by blurring, darkening, lightening, or desaturation of peripheral portions of the image - The use of non-rectanglar matMat (picture framing)In the picture framing industry, a mat is a thin, flat piece of paper-based material included within a picture frame, which serves as additional decoration and to perform several other, more practical functions, such as separating the art from the glass...
or picture framePicture frameA picture frame is a decorative edging for a picture, such as a painting or photograph, intended to enhance it, make it easier to display, or protect it.-Construction:...
may be used for selection of portions of a larger image
Uncropping
It is not possible to "uncrop" a cropped 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, using texture synthesis
Texture synthesis
Texture synthesis is the process of algorithmically constructing a large digital image from a small digital sample image by taking advantage of its structural content...
, 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. An uncrop plug-in exists for the GIMP
GIMP
GIMP is a free software raster graphics editor. It is primarily employed as an image retouching and editing tool and is freely available in versions tailored for most popular operating systems including Microsoft Windows, Apple Mac OS X, and Linux.In addition to detailed image retouching and...
image editor.