Workstation for displaying dynamic image with real-time special effects

A dynamic-image displaying workstation provided with a display device for displaying an image, a video signal processing circuit for outputting dynamic-image data representing a dynamic image corresponding to a video signal, a first dual port memory for receiving and storing the dynamic-image data outputted from the video signal processing circuit, a second dual port memory for storing data representing pixels of an image to be displayed by the display device, and a third dual port memory for storing data representing a window area. The window area is an area of a window, to which the dynamic-image belongs, and is not covered by any other windows. The workstation is further provided with a fourth dual port memory for storing data representing a dynamic-image display effective area corresponding to the dynamic image represented by the dynamic-image stored in the first dual port memory, a data selector for receiving data read from the first dual port memory at a first input terminal thereof, and data read from the second dual port memory at a second input terminal thereof, for selecting one of the third and fourth dual port memories and receiving data read from the selected dual port memory at a third input terminal thereof, for selecting the data received at the first input terminal thereof if the data read from the third dual port memory is the data representing the window area, and the data read from the third dual port memory is the data representing the dynamic-image display effective area, for selecting the data received at the second input terminal thereof and for outputting a signal representing the selected data to the display device.

BACKGROUND OF THE INVENTION 
1. Field of The Invention 
This invention generally relates to a workstation, which employs a 
time-sharing/multi-tasking operating system (OS) such as UNIX 
(incidentally, UNIX is a registered trademark of American Telephone and 
Telegraph Corporation) and runs what is called a multiple-window system 
such as X windows (incidentally, X windows is a registered trademark of 
Massachusetts Institute of Technology (hereunder sometimes referred to as 
X window system)) and can display a dynamic image such as a video image in 
a specified window, (hereunder sometimes referred to as a dynamic-image 
displaying workstation) and more particularly to a dynamic-image 
displaying workstation which can perform a special-effect operation such 
as an automatic zooming, which requires a real time processing, in real 
time. 
2. Description of The Related Art 
In recent years, what is called a multi-media computer has been developed, 
which uses what is called time-based media such as audio media and video 
dynamic-images in addition to conventional media such as characters and 
graphic forms, with the intention of providing computer users with a 
computer which is easier to operate. 
Where such a multi-media computer is realized by employing a workstation 
which excels in interactive processing, the workstation sometimes runs a 
multiple-window system such as the X window system, and makes a video 
dynamic-image belong to (namely, contained in) and displayed in a window. 
Incidentally, when a video dynamic-image is made to belong to (namely, to 
be contained in) a window, if the window, to which the video dynamic-image 
belongs, is covered (or overlapped) by another window, a part or all of 
the video dynamic-image, which is contained in the overlapped part of the 
former window, is also covered by the latter window. Further, if the 
window, to which the video dynamic-image belongs, is moved, the video 
dynamic-image is similarly moved in such a manner not to change the 
position thereof in the moved window. Namely, the same processing is 
performed on a window and a video dynamic-image contained therein. 
Referring to FIG. 9, there is illustrated the configuration of such a 
conventional dynamic-image displaying workstation. 
A central processing unit (CPU) 12 of the conventional workstation runs 
(namely, executes) UNIX, which is a time-sharing/multi-tasking OS, and the 
X window system, which is what is called a multiple-window system. 
Further, the CPU 12 receives data from and sends data to a main memory and 
input/output (I/O) devices such as a hard disk through a data bus 14. Dual 
port memories 1, 2 and 34 are conventional graphic frame memories, each of 
which usually consists of a video random-access-memory (VRAM). Further, 
data can be read from and written to a first port (namely, a left port as 
viewed in this figure) of each of the memories 1, 2 and 34. Furthermore, 
data can be read from a second port (namely, a right port as viewed in 
this figure) of each of the memories 1, 2 and 34. The number of pixels 
displayed horizontally and vertically on a display device of the 
workstation (namely, the resolution of the display device thereof) are 
1280 and 1024, respectively. The memories (hereunder sometimes referred to 
as the buffers) 1, 2 and 34 store 24-bit data, 8-bit data and 1-bit data 
corresponding to each pixel, respectively. Analog data represented by 
video signals (more particularly, National Television System Committee 
(NTSC) composite video signals in this case) inputted from an external 
device are converted by a video-signal processing circuit 9 into digital 
data. Then, a predetermined processing is further performed therein and 
data corresponding to one field of a video image is outputted therefrom 
every (1/60) seconds. The CPU 12 sets control commands describing tile 
contents of the information on various processing to be performed on video 
signals. The contents of the information are, for example, positions on 
the screen of an external display device, which define an original picture 
including a video dynamic-image to be inputted to the workstation, the 
size of the input image, scaling parameters or factor, positions on the 
screen of a display device of the workstation, which define the video 
dynamic-image, the size of the video dynamic-image and contrast/luminance 
control parameters. The video signal processing circuit 9 writes data 
representing the video dynamic-image to the dual port memory 1 from the 
first port thereof and controls the data. The workstation has what is 
called a key plane of the memory 34 which serves to control whether or not 
the video image represented by the buffer or memory 1 is displayed on the 
screen of a color display device 8 and whether or not each pixel of 
graphic forms and characters represented by data stored in the buffer or 
memory 2 is displayed thereon. In case of this conventional workstation, a 
value of 1 is stored correspondingly to each pixel of the video 
dynamic-image at a corresponding location of the memory 34. In contrast, a 
value of 0 is stored correspondingly to each pixel of the graphic forms 
and characters at a corresponding location thereof. Further, the 
workstation translates 8-bit output data read from the memory 2, which 
indicates one of 256 kinds of colors, into 24-bit color data by using a 
color lookup table (or a color map) 6. A data selector 5 is practically a 
multiplexer 50 which selects color data originated from the memory 2 if 
input data S is 0 and selects color data originated from the memory 1 if 
input data S is 1. A signal representing output data of the data selector 
5 is converted by a digital-to-analog (D/A) converter 7 into an analog 
red-green-blue (RGB) video signal, from which a color image is then 
displayed on the screen of a color display 8. If an image-data reading 
control signal and an image-data reading address signal, which are 
synchronized with the video signal sent to the color display 8, are 
supplied to the D/A converter 7 and the memories, respectively, as 
illustrated in FIG. 9, a video dynamic-image (in this case, a dynamic 
image of jet planes) can be displayed in a window of the multiple-window, 
to which the dynamic image belongs, on the screen of the color display 8 
of this figure. At that time, the CPU 12 should write data representing 
the form of the part of the dynamic image, which is not covered by another 
window, to the key plane 34 quickly responding to a user's manipulation of 
a window. FIG. 9 illustrates a state in which the window containing the 
video dynamic-image is covered or screened by a pull-down menu window 
(hereunder sometimes referred to simply as a pull-down menu) which has a 
long length-ways rectangle. The pull-down menu is created and destroyed by 
manipulating a mouse of the workstation. Next, when the mouse is 
manipulated to destroy the pull-down menu in the state of FIG. 9, an event 
interruption is caused and delivered to the CPU 12. Then, the CPU 12 runs 
a window-manager program or application of the X window system so as to 
cause a sequence of operations of deleting data representing the pull-down 
menu form, which is stored in the memory 2, and filling up a rectangular 
empty space in the pattern stored in the memory 34. In case of relatively 
slow operations of, for instance, moving, resizing, creating or destroying 
a window in response to a user's manual manipulation of the mouse, the 
time-sharing/multi-tasking OS can barely follow such operations in real 
time. 
However, in case of the application of multi-media, special-effect 
functions such as an automatic zooming (namely, the function of performing 
automatic repetitions of zooming-in on/zooming-out from a part of a scene) 
and a spinning function (namely, the function of performing rotations of a 
part of a scene around a vertical axis and around a horizontal axis) are 
greatly demanded in addition to the function of displaying a video image 
of a fixed-shape like an ordinary television set in order to make an 
extremely effective impression on a viewer. Further, it is necessary for 
achieving such special effects to change the contents of the key plane 34 
in real time. Inconveniently, in case of employing the 
time-sharing/multi-tasking OS for processing many tasks concurrently, the 
CPU 12 cannot be dedicated to the rewriting of the contents of the key 
plane 34. Thus, if the number of tasks to be performed increases, for 
example, the automatic zooming cannot be effected smoothly. Unfavorably, 
the automatic zooming becomes performed discontinuously. 
The present invention is created to resolve such a problem of the 
conventional dynamic-image displaying workstation. 
It is, accordingly, an object of the present invention to provide a 
dynamic-image displaying workstation which operates under the control of a 
non-real-time OS and can display a video dynamic-image by using multiple 
windows and perform real-time special-effect functions. 
SUMMARY OF THE INVENTION 
To achieve the foregoing object and in accordance with the present 
invention, there is provided a dynamic-image displaying workstation in 
which a key plane is divided into two independent planes (for example, 
third and fourth planes 3 and 4 as illustrated in FIG. 1). Namely, one of 
the two planes is called a window-area plane which is used to write data 
representing a pattern of a window area. The window area is defined herein 
as an area of a window, to which a video dynamic-image belongs, and is not 
covered by any other windows. Further, the other of the two planes is 
called a dynamic-image area plane which is used to write data representing 
a pattern of a dynamic-image-display effective area thereto. The 
dynamic-image display effective area is defined herein as an area of the 
video dynamic-image, which is originally intended to be shown to a viewer. 
A part of the video dynamic-image corresponding to the result of the 
logical AND between the data representing the patterns respectively 
written to the window-area plane and the dynamic-image area plane is 
displayed on the screen of a display device of the workstation. 
Incidentally, only when a request for changing the window area is caused, 
data representing a pattern of a window area is written to the window-area 
plane by a processor (including the CPU), which processes the request 
(namely, runs a window-manager program). In contrast with this, data 
representing a pattern of a dynamic-image-display effective area is 
written to the dynamic-image area plane (at a relatively high speed) by a 
processor for running a dynamic-image area control program in real time 
independently of change in the window area. The logical AND between the 
data representing the patterns respectively written to the window-area 
plane and the dynamic-image area plane is automatically carried out by 
hardware. Thus the problem of the conventional workstation (namely, 
special-effect functions such as the automatic zooming are effected 
discontinuously) can be resolved. Thereby, even in case where a 
workstation operates under the control of a non-real-time 
time-sharing/multi-tasking OS, a video dynamic-image can be displayed by 
using multiple windows and performing real-time special-effect functions. 
Consequently, the dynamic-image displaying workstation of the present 
invention has outstanding merits in the application of multi-media using a 
dynamic image.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Hereinafter, preferred embodiments of the present invention will be 
described in detail by referring to the accompanying drawings. 
1. First Embodiment 
Hereinafter, the first embodiment of the present invention will be 
described in detail by referring to the drawings. 
FIG. 1 is a schematic block diagram for illustrating the configuration of 
the first embodiment of (namely, the first dynamic-image displaying 
workstation embodying) the present invention. In this figure, reference 
numerals 1 and 2 designate first and second dual port memories; 5 a data 
selector; 6 a color lookup table (device); 7 a D/A converter; 8 a color 
display; 9 a video signal processing circuit; 12 a CPU; 14 a first data 
bus; 50 a multiplexer; and 100 an image-reading-operation control device 
for outputting an image-data reading control signal and an image-data 
reading address signal. These composing elements have the same functions 
as the corresponding elements of the conventional workstation indicated by 
like reference numerals in FIG. 9 do. Namely, the CPU 12 of this 
workstation runs UNIX, which is a time-sharing/multi-tasking 0S, and the X 
window system, which is a multiple-window system. Further, the CPU 12 
receives data from and sends data to a main memory and I/O devices such as 
a hard disk through the data bus 14. Dual port memories 1, 2, 3 and 4 have 
functions similar to functions of a conventional graphic frame memories, 
each of which usually consists of a VRAM. Furthermore, data can be read 
from and written to a first port (namely, a left port as viewed in this 
figure) of each of the memories 1, 2, 3 and 4. Moreover, data can be read 
from a second port (namely, a right port as viewed in this figure) of each 
of the memories 1, 2, 3 and 4. The numbers of pixels displayed 
horizontally and vertically on a display device of the workstation 
(namely, the resolution of the display device thereof) are 1280 and 1024, 
respectively. The memories (hereunder sometimes referred to as the 
buffers) 1, 2, 3 and 4 store 24-bit data, 8-bit data, 1-bit data and 1-bit 
data corresponding to each pixel, respectively. Analog data represented by 
video signals (more particularly, NTSC composite video signals in case of 
this embodiment) inputted from an external device are converted by the 
video-signal processing circuit 9 into digital data. Then, a predetermined 
processing is further performed therein and data corresponding to one 
field of a video image is outputted therefrom every (1/60) seconds. The 
CPU 12 sets control commands describing the contents of the information on 
various processing to be performed on video signals. The contents of the 
information are, for example, positions on the screen of an external 
display device, which define an original picture including a video 
dynamic-image to be inputted to the workstation, the size of the input 
image, scaling parameters or factor, positions on the screen of a display 
device of the workstation, which define the video dynamic-image, the size 
of the video dynamic-image and contrast/luminance control parameters. The 
video signal processing circuit 9 writes data representing the video 
dynamic-image to the dual port memory 1 from the first port thereof and 
controls the data. For simplicity of description, a video dynamic image of 
jet planes having 640 pixels in the horizontal direction and 480 pixels in 
the vertical direction is pictorially illustrated in the dual port memory 
1 of FIG. 1. Further, data representing characters and graphic forms as 
shown in the screen of the display of the workstation is written by the 
CPU 12 to the second dual port memory 2. The color lookup table 6 inputs 
8-bit output data read from the memory 2, which indicates one of 256 kinds 
of colors, and immediately converts the 8-bit data inputted thereto into 
24-bit color data, in which three groups of 8 bits represent red (R), 
green (G) and blue (B) data, and outputs the 24-bit color data. Moreover, 
a value of 1 is written to the address of the third dual port memory 3 
corresponding to each pixel of a window area as defined previously. 
Furthermore, a value of 0 is written to the other addresses of the memory 
3. For convenience of description, this dual port memory 3 will be 
referred to as a window-area plane hereinbelow. Further, a value of 1 is 
written to the address of the fourth dual port memory 4 corresponding to 
each pixel of a dynamic-image display effective area corresponding to the 
video dynamic-image stored in the first dual memory 1. Incidentally, the 
dynamic-image display effective area is an area or part, which is intended 
to be shown to a viewer or utilized, of a dynamic image regardless of the 
form of the window, to which the dynamic image belongs, and of the 
overlapping of tile windows, as stated previously. Furthermore, a value of 
0 is written to the other addresses of the memory 4. For convenience of 
description, this dual port memory 4 will be referred to as a 
dynamic-image area plane hereunder. The data selector 5 practically 
consists of the multiplexer 50 and an AND gate circuit 51, which selects 
output data of the memory 1 if both of input data a and b are 1, and 
otherwise selects output data of the memory 2, and outputs the selected 
data. A signal representing output data of the data selector 5 is 
converted by the D/A converter 7 into an analog RGB video signal, from 
which a color image is then displayed on the screen of the color display 8 
having the resolution of 1280.times.1024 pixels. If an image-data reading 
control signal and an image-data reading address signal, which are 
synchronized with the video signal sent to the color display 8, are 
supplied from the device 100 to the D/A converter 7 and the second port of 
each of the memories 1, 2, 3 and 4, respectively, the data selector 5 
makes video dynamic-image data pass therethrough when data corresponding 
to pixels of an area or part obtained as the result of the logical AND 
between the data representing the window area stored in the window-area 
plane 3 and the data representing the dynamic-image area stored in the 
dynamic-image area plane 4. Thus, as illustrated in FIG. 1, a video 
dynamic-image (in this case, a dynamic image of jet planes) can be 
displayed in a window of the multiple-window, to which the dynamic image 
belongs, on the screen of the color display 8 of this figure. 
Hereinafter, it will be described in detail by referring to FIG. 8 how to 
utilize the bit patterns of the window area of the window-area plane 3 and 
of the dynamic-image display effective area of tile dynamic-image are 
plane 4. FIG. 8(A) shows an initial or original state of each of the dual 
port memories 1, 2, 3 and 4. First, if the window indicated by leftwardly 
descending oblique lines in the lower right part of the box corresponding 
to the memory 2 of FIG. 8(A) is enlarged in the foreground by manipulating 
a mouse or the like as illustrated in FIG. 8(B), a part of the window area 
shown in the box corresponding to the memory 3 of FIG. 8(A) covered by the 
enlarged part of the window is deleted as illustrated in the box 
corresponding to the memory 3 of FIG. 8(B). Even if there is no change in 
the dynamic-image display effective area of the memory 4 of FIGS. 8(A) and 
8(B), the logical AND between the window area and the dynamic-image 
effective area is automatically performed. This results in that the video 
dynamic-image can be correctly displayed in the color display 8. Next, 
when an automatic zooming is being performed (in this case, the 
contraction and expansion of the dynamic image of the jet planes are 
repeatedly effected) as illustrated in FIG. 8(C), the dynamic image 
changes in form or contour and so on (namely, the dynamic image of the box 
corresponding to the memory 1 of FIG. 8(C) contracts and expands 
repeatedly) in real time every (1/60) seconds at a maximum rate in 
response to an updating of control commands supplied to the video signal 
processing circuit 9. In response to such real-time change in form or 
contour of the dynamic image, the contents of the dynamic-image display 
effective area are rewritten momentarily as is shown in the box of the 
memory 4 of FIG. (C). Thus, even when there is no change in the window 
area (as shown in the box corresponding to the memory 3 of FIG. 8(C)), as 
a result of automatically effecting the logical AND between the window 
area and the dynamic-image display effective area, the dynamic image 
automatically zoomed in real time can be correctly displayed on the screen 
of the display of the workstation. 
2. Second Embodiment 
Hereinafter, the second embodiment of the present invention will be 
described in detail by referring to the drawings. 
FIG. 2 is a schematic block diagram for illustrating the configuration of 
the second embodiment of (namely, the second dynamic-image displaying 
workstation embodying) the present invention. In this figure, reference 
numerals 1, 2, 3 and 4 designate first, second, third and fourth dual port 
memories; 5 a data selector; 6 a color lookup table (device); 7 a D/A 
converter; 8 a color display; 9 a video signal processing circuit; 12 a 
CPU; 14 a first data bus; 50 a multiplexer; 51 an AND gate circuit; and 
100 an image-reading-operation control device for outputting an image-data 
reading control signal and an image-data reading address signal. These 
composing elements have the same functions as the corresponding elements 
of the first dynamic-image displaying workstation indicated by like 
reference numerals in FIG. 1 do. Namely, the CPU 12 of this workstation 
runs UNIX, which is a time-sharing/multi-tasking OS, and the X window 
system, which is a multiple-window system. Further, reference numeral 13 
denotes a processor for executing an instruction down-loaded by the CPU 12 
to an instruction/data memory 16 independently of the CPU 12. Reference 
numeral 15 designates a second data bus, through which the processor 13 
sets a control command (namely, the contents of a processing to be 
performed on a video signal) in the video signal processing circuit 9 and 
writes data representing a dynamic-image display effective area to the 
fourth dual port memory 4. Further, reference numeral 17 represents a bus 
interface circuit. When the CPU releases the second data bus 15, the CPU 
12 can access data on the second data bus 15 through the first data bus 14 
and the bus interface circuit 17 by issuing a request to the circuit 17. 
In case of this embodiment, this bus interface circuit 17 is used when the 
CPU downloads instructions and data prepared for the processor 13 to the 
instruction/data memory 16. The video signal processing circuit 9 writes 
data representing a video dynamic-image to first dual port memory 1 from 
the first port thereof and controls the data. Further, data representing a 
character or a graphic form is written by the CPU 12 to the second dual 
port memory 2. Moreover, data representing a window area is written by the 
CPU 12 to the third dual port memory 3 (namely, a window-area plane). 
Furthermore, data representing a dynamic-image display effective area is 
written by the processor 13 to the fourth dual port memory 4 (namely, a 
dynamic-image area plane). A part of the workstation, which includes the 
first to fourth dual port memories 1 to 4 and is illustrated in the right 
half of FIG. 2, operate in the same manner as in case of the first 
embodiment. Thus a video dynamic-image of jet planes, which belongs to 
multiple window, can be displayed on the screen of the color display 8. 
Next, an operation of the other part of the workstation illustrated in the 
left half of FIG. 2 will be described hereinbelow. First, the CPU 12 sends 
a request for the acquisition of the second data bus 15 to the bus 
interface circuit 17 and then downloads to the instruction/data memory 16 
a group of routines for generating data representing a pattern of the 
dynamic-image display effective area to be written to the dynamic-image 
area plane 4, as well as a sequence of control commands to be provided to 
the video signal processing circuit 9. Upon completion of the downloading, 
the CPU 12 releases the second data bus 15 and gives back the 
proprietorship of the second data bus to the processor 13. Thereafter, 
when a request for updating the state of the window containing the dynamic 
image is caused due to the phenomena that the window becomes covered by 
another window, or that the window is moved, the CPU 12 writes data 
representing new graphic forms to the second dual port memory 2 and also 
writes data representing a new window area to the window-area plane 3. 
Simultaneously, if the updating of the state of the window affects the 
dynamic image, the CPU 12 immediately directs the processor 13 through the 
bus interface circuit 17 (by, for instance, generating an interrupt) to 
run an appropriate processing routine. Processing to be performed by 
running the processing routine is, for example, to set a group of new 
control commands in the video signal processing circuit 9, or to write a 
group of new patterns of the dynamic-image effective area to the 
dynamic-image area plane 4. 
This embodiment is characterized in that with respect to operations, which 
do not require a quick response, such as an interactive operation between 
the workstation and a user, the CPU 12 perform the updating operation by 
rewriting the contents of the second dual port memory 2 and of the 
window-area plane 3 and that on the other hand, in connection with other 
operations, which require quick responses and are fatally affected by 
delay in responding, such as real-time special-effect operation (for 
instance, an automatic zooming), the processor 13, which can operate 
independently of the CPU 12, performs the updating operation on the video 
signal processing circuit 9 and the dynamic-image area plane at a high 
speed in real time. This ensures more reliably that a special-effect 
operation can be performed on the dynamic image in real time. 
Incidentally, the instruction/data memory 16 is connected only to the 
second data bus 15 as illustrated in FIG. 2. However, the present 
invention is not limited to such a configuration. For instance, a dual 
port memory connected to both of the first and second data buses 14 and 15 
may be employed. In case of employing such a dual port memory, preferably, 
there occurs no overhead required for the acquisition of the second data 
bus 15. 
3. Third Embodiment 
Hereinafter, the third embodiment of the present invention will be 
described in detail by referring to the drawings. 
FIG. 3 is a schematic block diagram for illustrating the configuration of 
the third embodiment of (namely, the third dynamic-image displaying 
workstation embodying) the present invention. In this figure, reference 
numerals 1, 2, 3 and 4 designate first, second, third and fourth dual port 
memories; 5 a data selector; 6 a color lookup table (device); 7 a D/A 
converter; 8 a color display; 9 a video signal processing circuit; 12 a 
CPU; 14 a first data bus; 50 a multiplexer; 51 an AND gate circuit; and 
100 an image-reading-operation control device for outputting an image-data 
reading control signal and an image-data reading address signal. These 
composing elements have the same functions as the corresponding elements 
of the first dynamic-image displaying workstation indicated by like 
reference numerals in FIG. 1 do. Further, reference numeral 13 denotes a 
processor; 15 a second data bus; 16 an instruction/data memory; and 17 a 
bus interface circuit. These composing elements have the same functions as 
the corresponding elements of the second dynamic-image displaying 
workstation indicated by like reference numerals in FIG. 2 do. Namely, the 
CPU 12 of this workstation runs UNIX, which is a 
time-sharing/multi-tasking OS, and client programs (namely, application 
programs) of the X window system, which is a multiple-window system. The 
processor 13 executes an instruction down-loaded by the CPU 12 to the 
instruction/data memory 16 independently of the CPU 12. The processor 13 
sets control commands (namely, the contents of a processing to be 
performed on a video signal) in the video signal processing circuit 9 and 
writes to the second to fourth dual port memories 2, 3 and 4 data 
corresponding to these memories, respectively. The video signal processing 
circuit 9 writes data representing a video dynamic-image to first dual 
port memory 1 from the first port thereof and controls the data. Further, 
data representing a character and a graphic form is written by the CPU 12 
to the second dual port memory 2. Moreover, data representing a window 
area is written by the CPU 12 to the third dual port memory 3 (namely, a 
window-area plane). Furthermore, data representing a dynamic-image display 
effective area is written by the processor 13 to the fourth dual port 
memory 4 (namely, a dynamic-image area plane). A part of the workstation, 
which includes the first to fourth dual port memories 1 to 4 and is 
illustrated in the right half of FIG. 3, operate in the same manner as in 
case of the first embodiment of FIG. 1. Thus a video dynamic-image of jet 
planes, which belongs to multiple window, can be displayed on the screen 
of the color display 8. 
Next, an operation of the other part of the workstation illustrated in the 
left half of FIG. 3 will be described hereinbelow. First, the CPU 12 
preliminarily sends a request for the acquisition of the second data bus 
15 to the bus interface circuit 17 and then downloads to the 
instruction/data memory 16 a group of routines (including a server program 
(for instance, a drawing routine) of the X window system) for generating 
data representing a graphic form and a character font to be written to the 
second dual port memory 2, a group of routines for generating a pattern of 
the window area to be written to the window-area plane 3, a group of 
routines for generating a pattern of the dynamic-image display effective 
area to be written to the dynamic-image area plane 4, and a sequence of 
control commands to be provided to the video signal processing circuit 9. 
Upon completion of the downloading, the CPU 12 releases the second data 
bus 15 and gives back the proprietorship of the second data bus to the 
processor 13. Thereafter, when a request for updating the state of the 
window containing the dynamic image is caused due to the phenomena that 
the window becomes covered by another window, or that the window is moved, 
the CPU 12 performs a suitable processing routine, for example, writes 
data representing new graphic forms to the second dual port memory 2 or 
writes data representing a new window area to the window-area plane 3. 
Further, if the updating of the state of the window affects the dynamic 
image, the CPU 12 immediately directs the processor 13 through the bus 
interface circuit 17 to set a group of new control commands in the video 
signal processing circuit 9 and write a group of new patterns of the 
dynamic-image effective area to the dynamic-image area plane at a high 
speed. That the processor can perform such operations at a high speed 
means that the processor can perform such operations continuously and 
straight as intended without "looking away" (namely, such operations can 
be prevented from being performed discontinuously). 
This embodiment is characterized in that the processor 13, which can 
operate independently of the CPU 12 running a non-real-time OS, is made to 
run a server program (including a drawing routine), and perform the 
updating operation on the video signal processing circuit 9 and the 
dynamic-image area plane 4 at a high speed in real time, and write to the 
second dual port memory 2 data required for effecting a drawing of a 
graphic form, and perform the updating operation on the window-area plane 
3 at a high speed in real time. This ensures more reliably that a 
special-effect operation can be performed on the dynamic image in real 
time and that a response to change in the state of the window, as well as 
a drawing of a graphic form, can be effected at a high speed. 
Incidentally, the instruction/data memory 16 is connected only to the 
second data bus 15 as illustrated in FIG. 3. However, the present 
invention is not limited to such a configuration. For instance, a dual 
port memory connected to both of the first and second data buses 14 and 15 
may be employed. In case of employing such a dual port memory, preferably, 
there occurs no overhead required for the acquisition of the second data 
bus 15. 
4. Fourth Embodiment 
Hereinafter, the fourth embodiment of the present invention will be 
described in detail by referring to the drawings. 
FIG. 4 is a schematic block diagram for illustrating the configuration of 
the fourth embodiment of (namely, the fourth dynamic-image displaying 
workstation embodying) the present invention. In this figure, reference 
numerals 1, 2, 3 and 4 designate first, second, third and fourth dual port 
memories; 5 a data selector; 6 a color lookup table (device); 7 a D/A 
converter; 8 a color display; 9 a video signal processing circuit; 12 a 
CPU; 14 a first data bus; 50 a multiplexer; 51 an AND gate circuit; and 
100 an image-reading-operation control device for outputting an image-data 
reading control signal and an image-data reading address signal. These 
composing elements have the same functions as the corresponding elements 
of the first dynamic-image displaying workstation indicated by like 
reference numerals in FIG. 1 do. Further, reference numeral 10 denotes a 
read/write control circuit, which is usually set to input dynamic-image 
data processed by and continually outputted from the video signal 
processing circuit 9 and to continually write the input dynamic-image data 
to the first dual port memory 1. Further, when the CPU 12 intends to read 
and process the video dynamic-image stored in the first dual port memory 1 
as a static image, the CPU 12 changes the conditions set in the circuit 10 
in such a manner to be able to read and write the data stored in the first 
dual port memory 1 through the first data bus 14. Moreover, the video 
signal processing circuit 9 of FIG. 4 is different from that of FIG. 1 in 
that the latter circuit 9 directly writes data representing a video 
dynamic-image to the first dual port memory 1, while the former circuit 9 
does not do that but outputs pixel address information on addresses 
corresponding to locations of the memory 1, to which data corresponding to 
pixels of the video dynamic image is written, as well as the data 
representing the video dynamic-image. When receiving the pixel address 
information, the read/write control circuit 10 carries out a writing 
operation appropriately. The CPU 12 of this workstation runs UNIX, which 
is a time-sharing/multi-tasking OS, and the X window system, which is a 
multiple-window system. The video signal processing circuit 9 writes data 
representing a video dynamic-image to first dual port memory 1 from the 
first port thereof and controls the data. 
In case of this embodiment, the key plane for displaying and controlling a 
dynamic image is divided into the window-area plane, which is written and 
updated only when the state of the window is changed, and a dynamic-image 
area plane which can be written and updated in real time completely 
irrespectively of change in the state of the window. Thereby, similarly as 
in case of the first embodiment, even in case where a workstation operates 
under the control of a non-real-time time-sharing/multi-tasking OS, a 
video dynamic-image can be displayed by using multiple window and 
performing real-time special-effect functions very smoothly. 
This embodiment is characterized in that the read/write control circuit 10 
is provided in the workstation and thereby, the dynamic-image data stored 
in the first dual port memory 1 can be accessed by the CPU 12 when the 
dynamic image represented by the dynamic-image data, which is usually made 
to move continually, is stopped (namely, freezed) and is utilized as a 
static image. Consequently, this dynamic-image displaying workstation has 
outstanding merits in the application of multi-media using a dynamic 
image. 
5. Fifth Embodiment 
Hereinafter, the fifth embodiment of the present invention will be 
described in detail by referring to the drawings. 
FIG. 5 is a schematic block diagram for illustrating the configuration of 
the fifth embodiment of (namely, the fifth dynamic-image displaying 
workstation embodying) the present invention. In this figure, reference 
numerals 1, 2, 3 and 4 designate first, second, third and fourth dual port 
memories; 5 a data selector; 6 a color lookup table (device); 7 a D/A 
converter; 8 a color display; 9 a video signal processing circuit; 12 a 
CPU; 14 a first data bus; 50 a multiplexer; 51 an AND gate circuit; and 
100 an image-reading-operation control device for outputting an image-data 
reading control signal and an image-data reading address signal. These 
composing elements have the same functions as the corresponding elements 
of the first dynamic-image displaying workstation indicated by like 
reference numerals in FIG. 1 do. Further, reference numeral 13 denotes a 
processor; 15 a second data bus; 16 an instruction/data memory; and 17 a 
bus interface circuit. These composing elements have the same functions as 
the corresponding elements of the second dynamic-image displaying 
workstation indicated by like reference numerals in FIG. 2 do. Moreover, 
reference numeral 10 denotes a read/write control circuit which has the 
same function as the circuit 10 of the fourth embodiment of FIG. 4. The 
CPU 12 of this workstation runs UNIX, which is a 
time-sharing/multi-tasking OS, and the X window system, which is a 
multiple-window system. The processor 13 can execute an instruction 
down-loaded by the CPU 12 to the instruction/data memory 16 independently 
of the CPU 12. The read/write control circuit 10, which is usually set to 
input dynamic-image data processed by and continually outputted from the 
video signal processing circuit 9 and to continually write the input 
dynamic-image data to the first dual port memory 1. Further, data 
representing a character and a graphic form is written by the CPU 12 to 
the second dual port memory 2. Moreover, data representing a window area 
is written by the CPU 12 to the third dual port memory 3 (namely, a 
window-area plane). Furthermore, data representing a dynamic-image display 
effective area is written by the processor 13 to the fourth dual port 
memory 4 (namely, a dynamic-image area plane). A part of the workstation, 
which includes the first to fourth dual port memories 1 to 4 and is 
illustrated in the right half of FIG. 5, operate in the same manner as in 
case of the first embodiment of FIG. 1. Thus a video dynamic-image of jet 
planes, which belongs to multiple window, can be displayed on the screen 
of the color display 8. 
Next, an operation of the other part of the workstation illustrated in the 
left half of FIG. 5 will be described hereinbelow. First, the CPU 12 sends 
a request for the acquisition of the second data bus 15 to the bus 
interface circuit 17 and then downloads to the instruction/data memory 16 
a group of routines for generating data representing a pattern of the 
dynamic-image display effective area to be written to the dynamic-image 
area plane 4, as well as a sequence of control commands to be provided to 
the video signal processing circuit 9. Upon completion of the downloading, 
the CPU 12 releases the second data bus 15 and gives back the 
proprietorship of the second data bus to the processor 13. Thereafter, 
when a request for updating the state of the window containing the dynamic 
image is caused due to the phenomena that the window becomes covered by 
another window, or that the window is moved, the CPU 12 writes data 
representing new graphic forms to the second dual port memory 2 and also 
writes data representing a new window area to the window-area plane 3. 
Simultaneously, if the updating of the state of the window affects the 
dynamic image, the CPU 12 immediately directs the processor 13 through the 
bus interface circuit 17 (by, for instance, generating an interrupt) to 
run an appropriate processing routine. Processing to be performed by 
running the processing routine is, for example, to set a group of new 
control commands in the video signal processing circuit 9, or to write a 
group of new patterns of the dynamic-image effective area to the 
dynamic-image area plane 4. 
This embodiment is characterized in that with respect to operations which 
do not require a quick response, such as an interactive operation between 
the workstation and a user, the CPU 12 perform the updating operation by 
rewriting the contents of the second dual port memory 2 and of the 
window-area plane 3 and that on the other hand, in connection with other 
operations, which require quick responses and are fatally affected by 
delay in responding, such as real-time special-effect operation (for 
instance, an automatic zooming), the processor 13, which can operate 
independently of the CPU 12, performs the updating operation on the video 
signal processing circuit 9 and the dynamic-image area plane at a high 
speed in real time. This ensures more reliably that a special-effect 
operation can be performed on the dynamic image in real time. This 
embodiment is further characterized in that the read/write control circuit 
10 is provided in the workstation and thereby, the dynamic-image data 
stored in the first dual port memory 1 can be accessed by the CPU 12 when 
the dynamic image represented by tile dynamic-image data, which is usually 
made to move continually, is stopped (namely, freezed) and is utilized as 
a static image. Consequently, this dynamic-image displaying workstation 
has outstanding merits in the application of multi-media using a dynamic 
image. 
Incidentally, the instruction/data memory 16 is connected only to the 
second data bus 15 as illustrated in FIG. 5. However, the present 
invention is not limited to such a configuration. For instance, a dual 
port memory connected to both of the first and second data buses 14 and 15 
may be employed. In case of employing such a dual port memory, preferably, 
there occurs no overhead required for the acquisition of the second data 
bus 15. 
6. Sixth Embodiment 
Hereinafter, the sixth embodiment of the present invention will be 
described in detail by referring to the drawings. 
FIG. 6 is a schematic block diagram for illustrating the configuration of 
the sixth embodiment of (namely, the sixth dynamic-image displaying 
workstation embodying) the present invention. In this figure, reference 
numerals 1, 2, 3 and 4 designate first, second, third and fourth dual port 
memories; 5 a data selector; 6 a color lookup table (device); 7 a D/A 
converter; 8 a color display; 9 a video signal processing circuit; 12 a 
CPU; 14 a first data bus; 50 a multiplexer; 51 an AND gate circuit; and 
100 an image-reading-operation control device for outputting an image-data 
reading control signal and an image-data reading address signal. These 
composing elements have the same functions as the corresponding elements 
of the first dynamic-image displaying workstation indicated by like 
reference numerals in FIG. 1 do. Further, reference numeral 13 denotes a 
processor; 15 a second data bus; 16 an instruction/data memory; and 17 a 
bus interface circuit. These composing elements have the same functions as 
the corresponding elements of the second dynamic-image displaying 
workstation indicated by like reference numerals in FIG. 2 do. Moreover, 
reference numeral 10 denotes a read/write control circuit which has the 
same function as the circuit 10 of the fourth embodiment of FIG. 4, but is 
connected to the second data bus 15 and thus the processor 13 can read 
dynamic-image data written to the first dual port memory 1 and write the 
dynamic-image data thereto. The CPU 12 of this workstation runs UNIX, 
which is a time-sharing/multi-tasking OS, and the X window system, which 
is a multiple-window system. The processor 13 can execute an instruction 
down-loaded by the CPU 12 to the instruction/data memory 16 independently 
of the CPU 12. The read/write control circuit 10, which is usually set to 
input dynamic-image data processed by and continually outputted from the 
video signal processing circuit 9 and to continually write the input 
dynamic-image data to the first dual port memory 1. Further, data 
representing a character and a graphic form is written by the CPU 12 to 
the second dual port memory 2. Moreover, data representing a window area 
is written by the CPU 12 to the third dual port memory 3 (namely, a 
window-area plane). Furthermore, data representing a dynamic-image display 
effective area is written by the processor 13 to the fourth dual port 
memory 4 (namely, a dynamic-image area plane). A part of the workstation, 
which includes the first to fourth dual port memories 1 to 4 and is 
illustrated in the right half of FIG. 6, operate in the same manner as in 
case of the first embodiment of FIG. 1. Thus a video dynamic-image of jet 
planes, which belongs to multiple window, can be displayed on the screen 
of the color display 8. 
Next, an operation of the other part of the workstation illustrated in the 
left half of FIG. 6 will be described hereinbelow. First, the CPU 12 sends 
a request for the acquisition of the second data bus 15 to the bus 
interface circuit 17 and then downloads to the instruction/data memory 16 
a group of routines for generating data representing a pattern of the 
dynamic-image display effective area to be written to the dynamic-image 
area plane 4, a sequence of control commands to be provided to the video 
signal processing circuit 9, and a group of routines for changing the 
conditions set in the read/write control circuit 10 and transferring, 
processing and storing data representing a freezed static image stored in 
the first dual port memory 1. Upon completion of the downloading, the CPU 
12 releases the second data bus 15 and gives back the proprietorship of 
the second data bus to the processor 13. Thereafter, when a request for 
updating the state of the window containing the dynamic image is caused 
due to the phenomena that the window becomes covered by another window, or 
that the window is moved, the CPU 12 writes data representing new graphic 
forms to the second dual port memory 2 and also writes data representing a 
new window area to the window-area plane 3. Simultaneously, if the 
updating of the state of the window affects the dynamic image, the CPU 12 
immediately directs the processor 13 through the bus interface circuit 17 
(by, for instance, generating an interrupt) to run an appropriate 
processing routine. Processing to be performed by running the processing 
routine is, for example, to set a group of new control commands in the 
video signal processing circuit 9, or to write a group of new patterns of 
the dynamic-image effective area to the dynamic-image area plane 4. 
This embodiment is characterized in that with regard to operations, which 
do not require a quick response, such as an interactive operation between 
the workstation and a user, the CPU 12 perform the updating operation by 
rewriting the contents of the second dual port memory 2 and of the 
window-area plane 3 and that on the other hand, in connection with other 
operations, which require quick responses and are fatally affected by 
delay in responding, such as real-time special-effect operation (for 
instance, an automatic zooming), the processor 13, which can operate 
independently of the CPU 12, performs the updating operation on the video 
signal processing circuit 9 and the dynamic-image area plane at a high 
speed in real time. This ensures more reliably that a special-effect 
operation can be performed on the dynamic image in real time. This 
embodiment is further characterized in that the read/write control circuit 
10 is provided in the workstation and thereby, the dynamic-image data 
stored in the first dual port memory 1 can be accessed by the processor 13 
when the dynamic image represented by the dynamic-image data, which is 
usually made to move continually, is stopped (namely, freezed) at a given 
moment and is utilized as a static image. Consequently, this dynamic-image 
displaying workstation has outstanding merits in the application of 
multi-media using a dynamic image, for example, in case where a video 
dynamic-image taken by a video camera is sampled and recognized every 0.5 
seconds (or every second) and the execution of a special processing 
routine for, for instance, issuing a predetermined message or a warning 
sound is started when an image meeting a predetermined condition, for 
instance, an image of a red object occupying nearly the entire screen of 
the display is received. 
Incidentally, the instruction/data memory 16 is connected only to the 
second data bus 15 as illustrated in FIG. 6. However, the present 
invention is not limited to such a configuration. For instance, a dual 
port memory connected to both of the first and second data buses 14 and 15 
may be employed. In case of employing such a dual port memory, preferably, 
there occurs no overhead required for the acquisition of the second data 
bus 15. 
7. Seventh Embodiment 
Hereinafter, the seventh embodiment of the present invention will be 
described in detail by referring to the drawings. 
FIG. 7 is a schematic block diagram for illustrating the configuration of 
the seventh embodiment of (namely, the seventh dynamic-image displaying 
workstation embodying) the present invention. In this figure, reference 
numerals 1, 2, 3 and 4 designate first, second, third and fourth dual port 
memories; 5 a data selector; 6 a color lookup table (device); 7 a D/A 
converter; 8 a color display; 9 a video signal processing circuit; 12 a 
CPU; 14 a first data bus; 50 a multiplexer; 51 an AND gate circuit; and 
100 an image-reading-operation control device for outputting an image-data 
reading control signal and an image-data reading address signal. These 
composing elements have the same functions as the corresponding elements 
of the first dynamic-image displaying workstation indicated by like 
reference numerals in FIG. 1 do. Further, reference numeral 13 denotes a 
processor; 15 a second data bus; 16 an instruction/data memory; and 17 a 
bus interface circuit. These composing elements have the same functions as 
the corresponding elements of the second dynamic-image displaying 
workstation indicated by like reference numerals in FIG. 2 do. Moreover, 
reference numeral 10 denotes a read/write control circuit which has the 
same function as the circuit 10 of the fourth embodiment of FIG. 4, but is 
connected to the second data bus 15 and thus the processor 13 can read 
dynamic-image data written to the first dual port memory 1 and write the 
dynamic-image data thereto. The CPU 12 of this workstation runs UNIX, 
which is a time-sharing/multi-tasking OS, and the client programs of the X 
window system, which is a multiple-window system. The processor 13 can 
execute an instruction down-loaded by the CPU 12 to the instruction/data 
memory 16 independently of the CPU 12. The processor 13 sets control 
commands (namely, the contents of a processing to be performed on a video 
signal) in the video signal processing circuit 9 and writes to the second 
to fourth dual port memories 2, 3 and 4 data corresponding to these 
memories, respectively. The read/write control circuit 10, which is 
usually set to input dynamic-image data processed by and continually 
outputted from the video signal processing circuit 9 and to continually 
write the input dynamic-image data to the first dual port memory 1. 
Further, data representing a character and a graphic form is written by 
the CPU 12 to the second dual port memory 2. Moreover, data representing a 
window area is written by the CPU 12 to the third dual port memory 3 
(namely, a window-area plane). Furthermore, data representing a 
dynamic-image display effective area is written by the processor 13 to the 
fourth dual port memory 4 (namely, a dynamic-image area plane). A part of 
the workstation, which includes the first to fourth dual port memories 1 
to 4 and is illustrated in the right half of FIG. 7, operate in the same 
manner as in case of the first embodiment of FIG. 1. Thus a video 
dynamic-image of jet planes, which belongs to multiple window, can be 
displayed on the screen of the color display 8. 
Next, an operation of the other part of the workstation illustrated in the 
left half of FIG. 7 will be described hereinbelow. First, the CPU 12 
preliminarily sends a request for the acquisition of the second data bus 
15 to the bus interface circuit 17 and then downloads to the 
instruction/data memory 16 a group of routines (including a server program 
(for instance, a drawing routine) of the X window system) for generating 
data representing a graphic form and a character font to be written to the 
second dual port memory 2, a group of routines for generating a pattern of 
the window area to be written to the window-area plane 3, a group of 
routines for generating a pattern of the dynamic-image display effective 
area to be written to the dynamic-image area plane 4, a sequence of 
control commands to be provided to the video signal processing circuit 9 
and a group of routines for changing the conditions set in the read/write 
control circuit 10 and transferring, processing and storing data 
representing a freezed static image stored in the first dual port memory 
1. Upon completion of the downloading, the CPU 12 releases the second data 
bus 15 and gives back the proprietorship of the second data bus to the 
processor 13. Thereafter, when a request for updating the state of the 
window containing the dynamic image is caused due to the phenomena that 
the window becomes covered by another window, or that the window is moved, 
the CPU 12 performs a suitable processing routine, for example, writes 
data representing new graphic forms to the second dual port memory 2 or 
writes data representing a new window area to the window-area plane 3. 
Further, if the updating of the state of the window affects the dynamic 
image, the CPU 12 immediately directs the processor 13 through the bus 
interface circuit 17 to set a group of new control commands in the video 
signal processing circuit 9 and write a group of new patterns of the 
dynamic-image effective area to the dynamic-image area plane at a high 
speed. As previously stated, that the processor can perform such 
operations at a high speed means that the processor can perform such 
operations continuously and straight as intended without "looking away" 
(namely, such operations can be prevented from being performed 
discontinuously). 
This embodiment is characterized in that the processor 13, which can 
operate independently of the CPU 12 running a non-real-time OS, is made to 
run a server program (including a drawing routine), and perform the 
updating operation on the video signal processing circuit 9 and the 
dynamic-image area plane 4 at a high speed in real time, and write to the 
second dual port memory 2 data required for effecting a drawing of a 
graphic form, and perform the updating operation on the window-area plane 
3 at a high speed in real time. This ensures more reliably that a 
special-effect operation can be performed on the dynamic image in real 
time and that a response to change in the state of the window, as well as 
a drawing of a graphic form, can be effected at a high speed. This 
embodiment is further characterized in that the read/write control circuit 
10 is provided in the workstation and thereby, the dynamic-image data 
stored in the first dual port memory 1 can be accessed by the processor 13 
when the dynamic image represented by the dynamic-image data, which is 
usually made to move continually, is stopped (namely, freezed) at a given 
moment and is utilized as a static image. Consequently, this dynamic-image 
displaying workstation has outstanding merits in the application of 
multi-media using a dynamic image, for example, in case where a video 
dynamic-image taken by a video camera is sampled and recognized every 0.5 
seconds (or every second) and the execution of a special processing 
routine for, for instance, displaying an image of a predetermined design 
or a warning sound is started when an image meeting a predetermined 
condition, for instance, an image of a red object occupying nearly the 
entire screen of the display is received. 
Incidentally, the instruction/data memory 16 is connected only to the 
second data bus 15 as illustrated in FIG. 7. However, the present 
invention is not limited to such a configuration. For instance, a dual 
port memory connected to both of the first and second data buses 14 and 15 
may be employed. In case of employing such a dual port memory, preferably, 
there occurs no overhead required for the acquisition of the second data 
bus 15. 
While preferred embodiments of the present invention have been described 
above, it is to be understood that the present invention is not limited 
thereto and that other modifications will be apparent to those skilled in 
the art without departing from the spirit of the invention. The scope of 
the present invention, therefore, is to be determined solely by the 
appended claims.