Cropping
Cropping [ ˈkɹɒpɪŋ ] (English for "cutting off, trimming") is the cutting of the edges of an image in order to adopt the image format in another format without creating black edges or having to distort the image . In particular, the film certain are aspect ratios (aspect ratio) to be considered.
Movie
This method is often used when porting movies for television. The overhang from the 16: 9 picture in the movie to the 4: 3 picture on television is cut off. " Letterboxing " is prevented, but image information is lost. This loss of information becomes clear in the opening credits when part of the name can no longer be recognized because it is outside the 4: 3 picture (the word Image can be seen on the "1.33: 1 picture" on the right) : Bryce Canyon National Park is only partially visible). Since it is customary to crop the films, especially with the 2.35: 1 picture to 1.85: 1 (16: 9), care is usually taken during filming that at least all important information is visible in the 16: 9 frame are. There is a safe area for this , which shows the cameraman and the director the current camera image on an extra monitor, but with the aspect ratio frame overlaid. Films broadcast on television or on DVD in their original aspect ratio are also known as Original Aspect Ratio (OAR). Filmmakers do not like it when broadcasters adapt the aspect ratio to their broadcast format on their own initiative. Conversely there are z. B. DVD releases in which the image content of a widescreen film is reduced (only) during the opening and closing credits (which results in an additional black frame all around compared to the original format) that it can also be viewed on a television or monitor in 4: 3 -Format all texts and names are visible; One example is the DVD release of Brust oder Keule by Universum Film GmbH & Co.KG in 2004 (2.35: 1, anamorphic coding, PAL, regional code 2).
Automatic - manual
With new releases (e.g. a 2.35: 1 movie for a 16: 9 DVD), cropping is often inevitable. In addition to selecting the target format, it is also necessary to decide between automatic and manual cropping:
Automatic cropping
The image section is specified once for the entire film and then no longer requires any changes during conversion. This is the cheapest, but it can destroy the composition of the picture. In extreme cases, entire scenes appear pointless; A typical example here are cinemascope westerns with duel scenes in which both duelists are outside the visible image in the 4: 3 TV version.
Manual cropping
The image section is determined for individual scenes or individual camera settings according to artistic criteria. Sometimes the image section is constantly shifted during a scene or letterboxing is accepted for individual scenes. The additional costs for this process are typically around € 1,000 for a 90-minute feature film; like color correction , it is mainly used for high-quality publications.
Examples
2.35: 1 picture with letterbox brought to 4: 3, the whole picture is visible.
1.85: 1 picture brought to 4: 3 with letterbox. Typical 16: 9 picture, the entire picture is no longer visible.
1.55: 1 picture brought to 4: 3 with letterbox. Compromise between 16: 9 and 4: 3, often used in the UK.
1.33: 1 picture. Letterbox does not need to be inserted as it is already 4: 3. Hardly any image information is visible, especially with the lettering.
Explanation of the image structure:
- Frames represent the visible area of the respective aspect ratio.
- Blue: 2.35: 1
- Red: 1.78: 1 (16: 9)
- Yellow: 1.55: 1 (14: 9)
- Green: 1.33: 1 (4: 3)
- The area of the image that is no longer visible after cropping is displayed darker.
- The frames of the larger aspect ratios are displayed; the frames that would be within the visible image are hidden so as not to disturb. The inserted "letter boxes" represent the picture in the 4: 3 aspect ratio as a percentage as it would appear on a 4: 3 television set. This is not similar to the picture on a 16: 9 TV.
Compromise
In Great Britain, 16: 9 films are occasionally "cropped" to 14: 9 (1.55: 1), in which a little of the image content is lost on the left and right, but only a small black stripe is created. This is also done the other way around at 4: 3, but the image content is shortened above and below. There is a general 16: 9 broadcasting requirement for new productions, but there are enough viewers with old 4: 3 televisions, and that is the reason for this compromise. In Germany there are hardly any programs in 14: 9. Either it is broadcast in 4: 3 or in the cinema wide formats 1.85: 1 and 2.35: 1. This does not include documentaries from "BBC exclusive".
Aspect Ratio Handling for Purchased Media in the United States
In the US there are even movie DVD releases in two versions of the same movie. In the original widescreen version, as it was also shown in the cinema, and as a 4: 3 Pan & Scan version. So you can decide whether you prefer to have the cinema feeling at home or prefer to have the screen completely and effectively filled.
High definition TV
With the introduction of HDTV and a fixed aspect ratio of 16: 9, a "cropping" of the 4: 3 picture of old material is used, in which the black stripes do not appear above and below the picture, but to the left and right of it.
Digital video
With digital video cameras (DV) it is used to save memory (an option many MJPEG cards), or because it is the DV standard with 704 visible lines, as opposed to the full PAL -Resolution so dictates.
image editing
During image processing, cropping creates an image section that does not necessarily have to have a fixed aspect ratio, as is the case with film. It can also be aligned outside the center of the image or vertically. The original aspect ratio can also be retained or a different one can be created by cropping to match the main motif. In addition to improving the image composition, cropping with a fixed aspect ratio is used to maintain a uniform appearance and the targeted adaptation to standard formats, e.g. B. for the expression.
