JPH06105226A - Picture synthesis device - Google Patents

Abstract

PURPOSE:To provide the inexpensive picture synthesis device whose control is simple without need for a transparent frame memory by selecting display priority of plural picture data outputted from plural picture frame memories and controlling a picture output. CONSTITUTION:A selection section 1 has a changeover circuit and a setting section 2 decides display priority for each picture frame according to the setting set based on a control signal and implements control to set forcibly a least significant bit with less effect on visual observation. A detection section 3 outputs picture data to a synthesis section 4 when display is allowed from a frame with higher display priority and all bits of the frame are ORed and when no bit is set, display is allowed to a subordinate detection section 3. When no display permission comes from a host detection section 3, the detection section 3 clears all bits of the frame. Then the synthesis section 4 ORs inputs from the detection section 3 to synthesize the picture data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image synthesizing device, and more particularly to an image synthesizing device for synthesizing a plurality of images by a computer.

[0002]

2. Description of the Related Art In a conventional image synthesizing apparatus having three image frames as shown in FIG. 2, in addition to the image frame memory, a display is made in pixel units corresponding to pixels in each frame. Three transparent frame memories 5 to set presence / absence
And a mask section 6 for controlling the presence / absence of display of three image data output from the image frame memory by the data of the transparent frame memory 5 corresponding to this data, and a synthesizing section 4 for synthesizing the output of the mask section 6. And have.

[0003]

In this conventional image synthesizing apparatus, since a transparent frame memory having the same number of bits as the number of pixels of the image frame to be synthesized is required, the number of memories to be used becomes large and the control is complicated. However, there is a problem in that it becomes unavoidable that it becomes expensive.

An object of the present invention is to eliminate the above-mentioned drawbacks and to provide an image synthesizing apparatus which does not require a transparent frame memory when synthesizing images and which is simple and inexpensive to control.

[0005]

An image synthesizing apparatus according to the present invention includes a selection unit which receives a control signal from the outside and selects a display priority of a plurality of image data output from a plurality of image frame memories, and an external unit. A detection unit that receives a control signal and detects the presence or absence of image data selected by the selection unit and controls image output; an image composition unit that combines images based on the output of the detection unit; And a setting unit for receiving the selection signal input required for selection and outputting the control signal.

Further, in the image synthesizing apparatus of the present invention, the detecting section outputs a mask signal for an image frame having a lower display priority based on the detection result of the presence or absence of the image data selected by the selecting section, and outputs the image. It has a configuration for controlling the output.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

In the embodiment shown in FIG. 1, a selection unit 1 for selecting the display priority of a plurality of image data output from a plurality of image frame memories (not shown), in this embodiment three image data of three image frames. And a setting unit 2 that receives a selection signal input from a host device such as a computer and outputs a control signal that controls the selection content of the selection unit 1, and an image of the selection unit 1 under the control of the control signal of the setting unit 2. It has a configuration including a detection unit 3 that selects the presence or absence of data and controls image output, and a combining unit 4 that combines image data based on the output of the detection unit 3.

Next, the operation of this embodiment will be described.

The selecting unit 1 has a switching circuit, determines the display priority for each image frame according to the setting set by the setting unit 2 based on the control signal, and forces the least significant bit which has little visual effect. The control is performed so that it stands up.

Next, the detecting section 3 synthesizes the image data if there is a display permission from a frame having a higher display priority.
And the logical sum of all the bits of the frame, and if none of the bits are set, the display permission is given to the lower detection unit 3. This permission is represented by a dotted arrow.

If the display is not permitted by the upper detector 36, the detector 3 drops all the bits of the frame.

Next, the synthesizing section 4 takes the logical sum of the inputs from the detecting section 3 to synthesize the image data.

In this way, image composition without the transparent frame memory becomes possible.

[0016]

As described above, according to the present invention, it is possible to omit the transparent frame memory when synthesizing image frames, and it is possible to realize an inexpensive image synthesizing apparatus which is easy to control.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an image synthesizing apparatus according to an exemplary embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional image synthesizing device.

[Explanation of symbols]

 1 selection unit 2 setting unit 3 detection unit 4 composition unit 5 transparent frame memory 6 mask unit

Claims (2)

[Claims] 1. A selection unit that receives a control signal from the outside and selects display priorities of a plurality of image data output from a plurality of image frame memories; and an image that receives a control signal from the outside and is selected by the selection unit. A detection unit that detects the presence or absence of data and controls image output, an image combination unit that combines images based on the output of the detection unit, and a display priority and selection required for the plurality of image data from a higher-level device. An image synthesizing apparatus comprising: a setting unit that receives the selection signal and outputs the control signal. 2. The detection unit outputs a mask signal for an image frame having a lower display priority based on the detection result of the presence or absence of the image data selected by the selection unit to control the image output. The image synthesizing apparatus according to claim 1.