1. Field of the Invention
The present invention relates to an image switching apparatus and an image switching method capable of performing switching and synthesis processing involving special effect processing, such as enlarge and reduce, for a plurality of input image signals, and a program recording medium.
2. Description of the Related Art
On broadcasting stations, or in the filed of video editing, or the like, so-called a switcher apparatus which performs switching, synthesis, and the like for a plurality of input video images from a video player or the like so as to output the resultant images has been widely used. Further, in recent years, the opportunity that switching and synthesis processing for video images, which is obtained by applying various special effects such as enlarge, reduce, and rotate, to input images through digital processing, is performed before output has been increased. Accordingly, a special effect apparatus that applies special effects to input image is more and more frequently used together with the switcher apparatus.
Hereinafter, an example of an image switching apparatus that uses the switcher apparatus and special effect apparatus to apply special effects to video images for output will be described. FIG. 1 schematically shows the configuration of a conventional image switching apparatus that the applicant of the present invention has filed previously (Patent Document 1: Jpn. Pat. Appln. Laid-Open Publication No. 2002-320140).
An image switching apparatus 300 shown in FIG. 1 includes: an image synthesis/switching section 310 serving as a switcher apparatus that performs switching of outputs and synthesis processing for a plurality of input image signals; a special effect processing section 320 which applies various special effects to the image signals from the image synthesis/switching section 310; a switching operation input section 330 for an operator to perform an input operation for the output switching and synthesis processing of the image synthesis/switching section 310; and a special effect operation input section 340 for the operator to perform the special effect processing of the special effect processing section 320. A combination of the image synthesis/switching section 310 and special effect processing section 320 allows the switching of output images and synthesis processing involving special effect processing to be realized in the image switching apparatus 300.
The image synthesis/switching section 310 includes: an input selection section 311 which selects a plurality of input image signals so as to connect to a plurality of output channels; a synthesis processing section 312 which applies various synthesis processing to image signals output from the input selection section 311; and a synthesis/switching controller 313 which controls the operations of the input selection section 311 and synthesis processing section 312. The input selection section 311 has a selection switch matrix 316 which allows respective input lines 314a to 314i to which a plurality of image signals are input from an external device to be connected to any of a plurality of input buses 315a to 315c connected to the synthesis processing section 312. With this configuration, a plurality of image signals output from an external device are selected and input to the synthesis processing section 312. The selection operation for the input images performed by the selection switch matrix 316 is controlled by the synthesis/switching controller 313. The number of the input lines 314a to 314i and that of the input buses 315a to 315c are not limited to the above.
The synthesis processing section 312 applies various image switching and synthesis processing to the image signals from the plurality of input buses 315a to 315c so as to output the image signals. Examples of the processing that the synthesis processing section 312 can perform include, in addition to standard image synthesis output processing, so-called keying, which is a technique used to superimpose one image on another, processing using so-called a wipe function (hereinafter, referred to wipe processing), which is a technique of switching images while moving the boundary between a base image and new image from one side to another, and the like. Further, the synthesis processing section 312 has a function of outputting arbitrary image signals among those on the plurality of input buses 315a to 315c to the special effect processing section 320. After the special effect processing section 320 applies various special effects to the image signals and outputs the resultant image signals to the synthesis processing section 312, the synthesis processing section 312 can perform the image switching and synthesis processing using the resultant image signals.
The synthesis processing section 312 performs predetermined image switching processing and synthesis processing according to, for example, a processing pattern set in advance. The processing pattern designates the type of the processing operation to be performed in the synthesis processing section 312. The type of the processing operation includes, for example, image switching using keying technique, image switching using wipe processing, and image switching by changing the ratio between images to be synthesized. Further, the processing pattern includes information designating the time-series transition of the processing operation. More specifically, this information designates how the boundary or ratio between an original image and new image to be synthesized is changed with time in image switching. The degree of the progress of the processing operation designated by the processing pattern is given as a progress ratio, where the initial state when the processing pattern is designated is set as 0% and the completion state of the processing operation after progress of the image switching and synthesis processing according to the designated processing pattern is set as 100%. In the synthesis processing section 312, the processing operation proceeds while the processing pattern or progress ratio is controlled by the synthesis/switching controller 313.
The synthesis/switching controller 313 controls the processing operations of the input selection section 311 and synthesis processing section 312 based on a control signal output from the switching operation input section 330. For example, the synthesis/switching controller 313 receives, from the switching operation input section 330, a control signal including pattern designation information that designates a processing pattern in the synthesis processing section 312, progress ratio designation information that designates a progress ratio of the processing operation corresponding to the designated processing pattern, and selection designation information that gives instruction on the input image selection switching operation in the selection switch matrix 316 and designates the processing operations in the input selection section 311 and synthesis processing section 312 to thereby control them.
The switching operation input section 330 has switches for designating the processing pattern and progress ratio in the synthesis processing section 312 and for giving instruction on the selection switching operation for input images in the input selection section 311 and the like. An operator's operation for the switches generates the pattern designation information, progress ratio designation information, and selection instruction information and sends them to the synthesis/switching controller 312. For example, the operator operates numerical keys, button switches or the like to designate the number of the processing pattern in the synthesis processing section 312 or the numbers of input lines 314a to 314i and input buses 315a to 315c to be connected to each other in the input selection section 311, or the operator operates fader switches to designate the progress ratio in the synthesis processing section 312. Further, the switching operation input section 330 can set the content of the processing pattern in the synthesis processing section 312 through the operator's operation for the switches.
The special effect processing section 320 has a function of applying, to the image output from the synthesis processing section 312, various special effect processing involving a digital computation such as enlarge, reduce, rotation, shift of display position, deform, change of color tone, emphasis on brightness change, and the like. In the special effect processing section 320, as in the case of the synthesis processing section 312, a processing pattern in which information on the type of the special effect and the transition of its operation has been previously set is designated by the special effect operation input section 340. Similarly, the progress ratio of the processing operation corresponding to the processing pattern is also controlled by the special effect operation input section 340.
The special effect operation input section 340 has switches for designating the processing pattern and its progress ratio in the special effect processing section 320. An operator's operation for the switches allows a control signal including the pattern designation information that designates the processing pattern for the special effect processing section 320 and progress ratio designation information that designates the progress ratio to be sent to the special effect processing section 320. As in the case of the switching operation input section 330, the operator operates, for example, numerical keys, button switches or the like to designate the number of the processing operation to be performed, or the operator operates fader switches to designate the progress ratio. Further, the special effect operation input section 340 can set the content of the processing pattern in the special effect processing section 320 through the operator's operation for the switches.
As described above, in the image switching apparatus 300, the operator's operation for the switching operation input section 330 and special effect operation input section 340 allows respective processing operations in the image synthesis/switching section 310 and special effect processing section 320 to be performed, thereby enabling the special effect processing section 320 to perform the display switching and synthesis processing involving special effects, such as keying or wipe processing.
When the processing pattern in the special effect processing section 320 is made corresponding to the processing pattern that designates the processing operation in the synthesis processing section 312 of the image synthesis/switching section 310, and the processing operation in the special effect processing section 320 is allowed to proceed according to the same progress ratio as that of the image synthesis/switching section 310, it is possible to allow the processing operation in the special effect processing section 320 to operate simultaneously with the processing operation in the synthesis processing section 312. In this case, common control information to both the image synthesis/switching section 310 and special effect processing section 320 is supplied from the switching operation input section 330 to the synthesis/switching controller 313, and the pattern designation information and progress ratio designation information is supplied to the special effect processing section 320 through the synthesis/switching controller 313. That is, it is possible for the operator to perform an operation control for the special effect processing section 320 and synthesis processing section 312 only through the switching operation input section 330.
In a conventional system having the configuration as shown in FIG. 1, the special effect processing section 320 is directly connected to the synthesis processing section 312, so that the special effect processing section 320 needs to be provided with a dedicated interface and a dedicated control method. This configuration increases operability and convenience; on the other hand, it is necessary to adopt and install the same manufacturer's special effect processing section 320 exclusively for the image switching apparatus 300.
Further, an image switching system, shown in FIG. 2, that uses a versatile special effect apparatus has also been widely used. In the image switching system shown in FIG. 2, an image switching apparatus 350 is constituted by an image synthesis/switching section 360 and switching operation input section 380. The image switching apparatus 350 is connected to an external special effect apparatus 370 through an SDI transmission path. The external special effect apparatus 370 is connected to a special effect operation input section 390 for the operator to perform an input operation for the special effect processing. In this system, the image switching apparatus 350 exchanges images with the external special effect apparatus 370 through the SDI transmission path. For this operation, the image switching apparatus 350 has an auxiliary output selection bus 366 for selectively outputting an auxiliary output to the external special effect apparatus 370.
In the above image switching system, the image switching apparatus 350 combines the image synthesis/switching section 360 and external special effect apparatus 370 to thereby realize switching of output images or synthesis processing involving special effect processing.
The image synthesis/switching section 360 includes an input selection section 361, a synthesis processing section 362 which applies various synthesis processing to an output image signal from the input selection section 361 so as to output the resultant image signal, and a synthesis/switching controller 363 which controls the operations of the input selection section 361 and synthesis processing section 362. The input selection section 361 has a matrix of selection switch matrix 366 which allows respective input lines 364a to 364i to which a plurality of image signals are input from an external device to be connected to any of a plurality of input buses 365a to 365c connected to the synthesis processing section 362. With this configuration, a plurality of image signals output from an external device are selected and input to the synthesis processing section 362. The selection operation for the input images performed by the selection switch matrix 366 is controlled by the synthesis/switching controller 363. The number of the input lines 364a to 364i and that of the input buses 365a to 365c are not limited to the above.
The selected image is output from the auxiliary output line (Aux output) provided in the image switching apparatus 350 through the auxiliary output selection bus 366. The output image is then input to the special effect apparatus 370 followed by processing for the image. The processed image is returned (as an output to which special effect processing has been applied) to one of the inputs of the image switching apparatus 350.
In the configuration as described above, the special effect apparatus 370 need not always be a product of the same manufacturer as the image switching apparatus 350. Further, in this configuration, the expensive special effect apparatus 370 can be connected to various types of image switching apparatuses installed at various locations, according to need.
The image switching apparatus 350 is used in order to, for example, switch images of a live TV broadcast, and is, therefore, required to have high operability so that an operator can select a desired image without fail. Further, in recent years, application of various special effects to images for broadcasting has been needed.