JPH06205375A - Scanning converion system - Google Patents

Abstract

PURPOSE:To attain easy to see picture for a part in motion by updating a non-interlace display frame in a timing when an even number field and an odd number field adjacent to each other timewise are updated and storing and updating both mean values in a field in motion and one preceding field. CONSTITUTION:Even and odd number memories 7, 8 are made up of buffers (Bu) A, B, a synchronizing separator section 2 detects an odd number field and the presence of a motion of the data is detected. When the motion is in existence, a memory control section 5 stores a mean value between input data obtained by each computing element and data of a field of two preceding frame to the Bu7A, 8A, and when no motion is in existence, the current input data are stored in the Bu7A, Bu8A as updated data. The data in the Bu7A, 8A form one frame, and when the separator section 2 detects an even number field, the memories are replaced with each other for the similar operation and the updated data are stored in the Bu7B, 8B or the Bu7B depending on the presence of motion. Thus, a portion having a motion is easily observed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scan conversion system for outputting an interlaced video signal such as NTSC or PAL to a personal computer, a workstation, or a non-interlaced display device having a higher definition. Is.

[0002]

2. Description of the Related Art Conventionally, in the case of converting an interlaced signal into a non-interlaced signal, a frame memory corresponding to the size of a display screen is prepared and every other line of the display is updated with an even field and an odd field. In this case, the lines are divided into lines to be updated, and only the lines assigned in each field are updated, and the display frame is updated at the timing when the update of one set of even and odd fields ends.

[0003]

In the conventional scan conversion as described above, the data in the even field and the data in the odd field forming the frame memory are the same even though there is a time lag. Since the frame is displayed in a non-interlaced manner, there is a problem that the tip of a moving portion changes into a comb-like shape and is difficult to see.

[0004]

In order to solve the above problems, a scan conversion system according to the present invention is a scan conversion system for outputting a moving image of an interlaced scanning system to a display device of a non-interlaced scanning system. Therefore, in order to write and display even fields and odd fields in the frame memory, one frame is always composed of even and odd fields that are temporally adjacent to each other, and a display frame is formed at the timing when one frame is established. When changing to the even or odd field, if the data of the input moving image in either the even or odd field to be updated is not close to the data at the same position in the previous frame, the motion If it is determined that there is a motion, and if there is a movement, the data of the field to be updated and the field of the compared field The average value calculated from the previous field and the data one level above or below the data is written as update data in the field to be updated and the immediately preceding field one level above or below that field. .

[0005]

Since the non-interlaced display frame is changed at the timing when the even and odd fields which are temporally adjacent to each other are updated, the time shift within the frame can be minimized, and the movement of the display image can be suppressed. Judgment is made by comparing the data between the two, and the average value of the field that has moved and the field immediately before it is written and updated in both fields, so only the moving part is filtered,
No change in comb teeth is visible.

[0006]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a scan conversion portion of an embodiment, FIG. 2 is a timing diagram of operation, and FIG. 3 is a diagram illustrating a model of a display frame.

In FIG. 1, 1 is a decoder for converting a composite signal such as NTSC or PAL into an analog signal such as RBG or YIQ, 2 is a sync separator for extracting a sync signal from the composite signal, and 3 is an RB from the decoder 1.
An A / D converter that converts an analog signal of G or YIQ into a digital signal based on the clock from the sync separator 2.
Is a data latch for synchronizing the data A / D converted by the A / D conversion unit 3 with the timing of memory control, 5 is a memory control unit for controlling the flow of the frame memory and the data based on the clock of the synchronization separation unit 2, 6 Is an address counter of the frame memory and is controlled by the memory controller 5.
Reference numeral 7 is an even memory of a double buffer configuration (buffers 7A and 7B) that constitutes a frame memory and records even lines, and 8 is an odd number of a double buffer configuration (buffers 8A and 8B) that constitutes a frame memory and records odd lines. It is a memory. One of the double buffers 7A, 8A (or 7
B, 8B) are operating for updating the input data, the other buffers 7B, 8B (or 7A, 8A) are alternately used for displaying the updated video signal. The even-numbered memory 7 and the odd-numbered memory 8 are read / written by the memory controller 5 at the address indicated by the address counter 6. Reference numeral 9 is a first selector for selecting data from the even memory 7 or odd memory 8, 10 is a second selector for selecting data from the even memory 7 or odd memory 8, and 11 is an output of the data latch 4 for obtaining an average value. And the first selector 9
, 12 is a divider for dividing the output of the adder 11 by a predetermined value to obtain an average value together with the adder 11, and 13 is a data latch 4 for detecting a motion.
Of the second selector 10 and a subtractor for obtaining the difference between the output of the second selector 10 and a comparator 14 for comparing the output of the subtractor 13 with a predetermined value to detect the movement together with the subtractor 13. The third selector 16 selects either the output of the field data from the data latch 4 or the average value from the divider 12 according to the result of the comparison, and 16 is the write data to the even memory 7 via the third selector 15. Is a data buffer and 17 is a data buffer for passing write data to the odd-numbered memory 8 via the third selector 15.

Now, the composite video signal is input to the decoder 1, and the decoder 1 converts this into an analog signal such as RGB or YIQ. Further, the composite video signal is input to the sync separator 2 to generate a horizontal sync signal, a vertical sync signal, a sampling clock, a valid data section signal, an even / odd discrimination signal, and the like. In accordance with the sampling clock generated by the sync separation unit 2, the A / D conversion unit 3 converts the analog signal output by the decoder 1 into a digital signal, and the data latch 4 captures this data.

The control in which the sync separator 2 detects an odd field and updates the data in the odd memory 8 will be described below with reference to FIGS. 1 and 2.

The memory controller 5 receives the odd-field determination signal from the sync separator 2 and, after the horizontal sync signal,
The memory address counter 6 is incremented during the valid data section signal. The memory address counter 6 is 1
The count of one field is completed after counting up to half the value of the pixels forming the frame. The memory address counter 6 is a buffer 7 of an even memory 7 and an odd memory 8.
A and 8A (the sync separation unit 2 operates to update the input data during detection of an odd field) have the same address, and the even memory 7 (buffer 7A) to be read
Is different from the data of the same address in the odd-numbered memory 8 (buffer 8A) by one line and has a positional relationship of one line above on the display surface (not shown). Here, one frame is composed of, for example, an even (2k) field and an odd number (2k + 1) field following it, and the next one frame is a next even (2 (k + 1)) field and an odd number (2 (k + 1)) following it. +1) field, and likewise always consists of adjacent even and odd fields.

Now, the data latch 4 outputs the data to be written, and the memory address counter 6 indicates the address where the data should be stored. Memory controller 5
Reads data from the buffer 7A of the even memory 7 and the buffer 8A of the odd memory 8. Now, from the buffer 8A of the odd-numbered memory 8, it is two frames before the data output from the data latch 4 ((C) to (A) of FIG. 2), and the sync separation unit 2 is an odd number. When a field is detected, the odd field data is read and output. The data read and output from the even memory 7 is the data of the even field ((B) of FIG. 2) which is one field before the read data of the buffer 8A of the odd memory 8.

Now, since the sync separator 2 detects an odd field, the second selector 10 selects the data of the odd memory 8 and the subtractor 13 writes an odd number from the data latch 4. The field data ((A) in FIG. 2) and the odd field data ((C) in FIG. 2) at the same position two frames before selected by the second selector 10 are input, and both data are subtracted. .

On the other hand, the first selector 9 selects the data of the buffer 7A of the even memory 7, and the adder 11 writes the data of the odd field to be written from the data latch 4 ((A) of FIG. 2). And the data selected by the first selector 9 (data from the same position one field before the field read from the buffer 8A of the odd-numbered memory 8 ((B) in FIG. 2)) is input, Add up,
The divider 12 divides by 2 and outputs the average value.

If the output of the subtractor 13 is smaller than a certain value in the comparator 14 considering noise and the like, the comparator 14
Detects no motion, selects the data output from the data latch 4 by the third selector 15, and the memory controller 5
Opens the data buffer 17 and writes the data in the buffer 8A of the odd-numbered memory 8.

On the other hand, when the output of the subtracter 13 is larger than a constant value in the comparator 14 in consideration of noise and the like, the comparator 14 detects that there is motion, and the third selector 15 causes the divider 12 to operate. Selects the average value data output by the memory controller 5, opens the data buffers 16 and 17, and writes and updates the data in the buffer 7A of the even memory 7 and the buffer 8A of the odd memory 8.

In this way, when the sync separation unit 2 detects an odd field, the average value of the current input data and a different field two frames before the current input data is detected by an even memory by detecting the motion of the odd field data. Buffer 7A of the odd number memory 8 and the buffer 8A of the odd number memory 8 are stored as the update data, one frame is established by each data, or the current input data is updated to the buffer 8A of the odd number memory 8 by no movement. By storing as, the data of the buffer 7A of the even memory 7 not updated and the data of the buffer 8A of the updated odd memory 8 form one frame.

When the sync separation unit 2 detects a change from the odd field to the even field, the memory control unit 5 changes the buffers 7A and 8A from the input data updating to the video signal displaying when one frame is established. The data is transferred to a display device (not shown) by DMA and displayed. On the other hand, when the sync separation unit 2 detects an even field, the memory of the above operation is exchanged and the same operation is performed. When there is no motion, the input even field data is stored in the buffer 7B of the even memory 7, When there is a motion, the update data is stored in the buffer 7B of the even memory 7 and the buffer 8B of the odd memory 8 corresponding to the line below it.

The model of the display frame shown in FIG. 3 will be described. In the figure, e attached to the left end of the line on the screen is an even line and o is an odd line. FIG. 3A shows a stationary rectangle. FIG. 3B shows a state in which when the rectangle moves to the right of the display screen, the present invention is not carried out and only the even field moves and the tip looks like a comb. FIG. 3C shows a case where the present invention is implemented. The average value of the moved part is calculated, the filter is applied there, and the odd and even fields are rewritten with the same data. Change.

[0019]

According to the present invention, in scan conversion for outputting a moving image of the interlaced scanning system to a display device of the non-interlaced scanning system, even numbers which are adjacent in time,
Since the non-interlaced display frame is changed at the timing when the odd number field is updated, the time shift within the frame can be minimized, and the movement of the display image is judged by comparing the data between the frames, Since the average value of the field that has moved and the field immediately before it is written and updated in both fields, only the moving part is filtered and the comb-like change does not appear.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a scan conversion unit according to an embodiment of the present invention.

FIG. 2 is a timing chart of the operation of the embodiment.

FIG. 3 is a diagram illustrating a model of a display frame.

[Explanation of symbols]

 5 memory control unit 6 memory address counter 7 even memory 8 odd memory 11 adder 12 divider 13 subtractor 14 comparator

Claims (1)

[Claims] 1. A scan conversion system for outputting a moving image of an interlaced scanning system to a display device of a non-interlaced scanning system, for writing even fields and odd fields in a frame memory for display. , One frame is composed of even and odd fields that are always adjacent in time, and the display frame is divided into even and
When changing to an odd field, if the data of the input moving image in either the even field or the odd field to be updated is not similar to the data at the same position in the previous frame, it means that there was motion. If it is determined that there is movement, the average value calculated for the data of the field to be updated and the data immediately above or below the compared field is updated. A scan conversion method, wherein data is written in the field to be updated and the immediately preceding field one above or below the field to be updated.