KR100706994B1 - A Method and Apparatus of FRC with field based for de-interlacing - Google Patents

Abstract

Disclosed is a method and apparatus for converting a frame rate when an input frame rate and an output frame rate are inconsistent in a digital TV. The present invention includes a field memory for writing an input signal in order, an input processing unit for outputting a state of the field memory, and a memory lead unit for reading in units of fields by determining a read area in which write and read pointers do not collide. do. Accordingly, the present invention has the effect of mitigating the unnaturalness of motion compared to the prior art, and implementing an operation of converting the frame rate using less memory.

De-Interlacing, Frame Rate Conversion, Field Memory

Description

A method and apparatus for converting frame rate by field for deinterlacing output {A Method and Apparatus of FRC with field based for de-interlacing}

1 is a view for explaining a frame rate conversion method when a conventional read is faster than a write;

2 is a view for explaining a frame rate conversion method when a conventional read is slower than a write;

3 is a block diagram showing an apparatus for converting a frame rate in units of fields for deinterlacing output according to the present invention;

4 is a view for explaining a frame rate conversion method when reading is faster than writing according to the present invention;

5 is a view for explaining a frame rate conversion method when reading is slower than writing according to the present invention;

<Description of the symbols for the main parts of the drawings>

100: input processing unit 120: field memory

140: memory lead unit 160: de-interlacing unit

The present invention relates to digital TV, and more particularly, to reduce the unnaturalness of motion by performing frame rate conversion on a field basis instead of frame rate conversion on a frame basis for de-interlacing output. A frame rate conversion method and apparatus for a field unit.

In general, interlacing is a method of scanning an image by scanning one or more scanning lines from the top to the bottom of the screen when the image is scanned and outputted as an electrical signal or displayed on a screen, and a progressive method is an image. When scanning and outputting as an electrical signal or displaying on the screen, it scans without skipping the scanning line from the top to the bottom of the screen in order. Therefore, in order to display an interlaced input signal such as NTSC or PAL on a progressive scan monitor, the interlaced scan image must be converted into a progressive scan image using a deinterlacing device.

In this deinterlacing method, the inter-interpolation method that inserts the immediately previous field information between the current field line information and fills the pixel values missing in one field into a complete frame, and the line of the current field itself. There is a line doubling method of repeatedly using information, and an intra-interpolation method using line interpolation of the current field itself.

On the other hand, when signals input to the system have a field rate of 60 Hz and signals output after signal processing are inconsistent with each other at a field rate of 59.94 Hz, frame rate conversion is performed using field / frame memory. : FRC). Through this, the frame format can be maintained, and the discontinuity can be prevented by the signal of another frame connected in the middle of the frame. In the case of interlaced I / O, the frame must be observed in units of frames. Therefore, frame repetition or skipping is performed.

In the conventional digital TV, when selecting a field for deinterlacing, the FRC algorithm that observes the order of even / odd fields by repeating or skipping frame by frame is used.

1 and 2 will be described the operation of the conventional FRC for de-interlacing. FIG. 1 illustrates a case where read is faster than write, and FIG. 2 illustrates a case where write is faster than read. 1 and 2 use 5 fields of memory, and read simultaneously reads the Previous, Current, and Next fields for deinterlacing. That is, when data is filled in memory of 1 to 4 fields, data of 1 field (previous), 2 fields (current), and 3 fields (next) is simultaneously read, and subsequent readings of the fields are performed. do.

1 is a case in which reading is faster than writing, and as the writing and reading continue, the 123 fields must be read and then the 234 fields are read as shown by the arrows. The four fields are being accessed, resulting in a conflict between the read and write pointers. Therefore, if it is determined that the read pointer may collide with the write pointer before reading the new field, the collision is avoided by repeating the frame which reads the first two fields 512 and 123 again. FIG. 2 shows that the write is faster than the read. If it is determined that the read pointer may collide with the write pointer before reading a new field as shown by the arrow, skip 123 and 234 fields in 512 fields. Skip the frame reading the field. By repeating and skipping such frames, the order of the radix / excellent field is maintained.

However, since the conventional FRC method is performed in a frame unit composed of two fields, an unnatural screen is output due to a phenomenon in which the movement of the image is reversed or rapidly skipped.

Accordingly, an object of the present invention is to solve the above-mentioned problems, and since the deinterlacing output is a sequential scan type, the FRC is performed in field units instead of frame units based on the fact that there is no distinction between odd and excellent. Disclosed is a method and apparatus for converting a frame rate on a field basis to relax.

In order to achieve the above object, the field-rate frame rate converting method for the deinterlacing output of the present invention, in the frame rate converting method, (1) writes an input video signal in the order of input into the field memory; Outputting the state of the field memory as a result, (2) checking which area the write pointer is accessing according to the signal output in step (1), and (3) confirming step (2) Determining a read area where the write and read pointers do not collide according to the result, and converting the frame rate by reading in units of fields, and (4) sequentially interlacing scan signals read from the field memory in step (3). Converting to a de-interlacing signal.

Field-rate frame rate conversion apparatus for de-interlacing output for achieving another object of the present invention is a frame rate conversion device, the input field for outputting the state of the field memory and the field memory to write the input signal in order Before reading a new field from the processing unit and the field memory, the state of the field memory is input from the input processing unit to determine a possibility of collision between a writing and a reading pointer, and the reading is repeated or skipped in units of fields according to the determination result. And a memory interleaving unit for converting and outputting a frame rate, and a deinterlacing unit performing deinterlacing using field information.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a block diagram of an apparatus for converting a frame rate in units of fields for deinterlacing output according to the present invention. The frame rate converter shown in FIG. 3 includes an input processor 100 and a field memory 120. The input processing unit 100 writes the interlaced scan-type image signals in the order input to the field memory 120, and transfers the result of the state of the field memory 120 to the memory lead unit 140. do. The field memory 120 serves as a frame buffer for deinterlacing and frame rate conversion. In addition, the apparatus of FIG. 3 includes a memory lead unit 140 and a deinterlacing unit 160. The memory read unit 140 simultaneously reads three fields (previous, present, and after) from the field memory 120 for deinterlacing. The deinterlacing unit 160 interpolates the current field using the information of the previous field and the next field read from the field memory 120. At this time, the interpolation offset is processed according to whether the current field is even or odd. An operation of the frame rate converter of FIG. 3 having such a configuration will be described in more detail with reference to FIGS. 4 and 5.

4 is a view for explaining a frame rate conversion method when the read is faster than the write according to the present invention, Figure 5 is a view for explaining a frame rate conversion method when the read is slower than the write.

When an interlaced video signal is input, the input processing unit 100 writes to the four field memories 120 in the order of input, and the memory lead unit 140 writes the state of the field memory 120 as a result. Will output The memory lead unit 140 starts reading when data is filled in the field memories 120 of 1 to 3. In this case, the memory lead unit 140 simultaneously reads information of three fields (previous, present, and after) from the field memory 120 for deinterlacing. Subsequently, the memory read unit 140 checks which area the write pointer to the field memory 120 accesses before starting to read a new field.

As shown in the portion indicated by the first arrow in FIG. 4, the memory lead unit 140 reads 341 fields from the field memory 120 and transfers the 341 fields to the deinterlacing unit 160. Subsequently, the memory lead unit 140 checks the access position of the write pointer to the field memory 120 before starting to read the 412 field. If the write pointer is accessing two fields, the read pointer may possibly collide with the write pointer. Judging by the case. When it is determined that there is a possibility of collision between the read pointer and the write pointer, the memory lead unit 140 performs field unit FRC that repeatedly reads information of 341 fields from the field memory 120 instead of the 412 fields, thereby providing the read pointer and the write pointer. Avoid collisions. Likewise, in the portion indicated by the second arrow of FIG. 4, the memory pointer 140 may read the 234 fields from the field memory 120, and then the access area of the write pointer may collide with one field before reading the next 341 fields. If this is confirmed, by repeatedly reading the information of the 234 fields, the collision between the read pointer and the write pointer is avoided.
In addition, as shown in FIG. 5, when the read is slower than the write, the memory lead unit 140 skips and reads one field from the field memory 120 when it is determined that the read pointer may collide with the write pointer. This avoids collisions between two pointers.

Therefore, even if the phase of the field output from the memory lead unit 140 is continuous and even or even or odd and continuous. However, the subsequent deinterlacing output is not a problem since it is a sequential scanning form in which the radix field and the even field are not distinguished, and the deinterlacing unit 160 offsets the interpolated data using the previous field and the subsequent field according to the current field information. )

On the other hand, the frame rate conversion according to the present invention can be implemented using a memory of four fields, which is less memory than the prior art. However, since repetition and skipping of the field are frequently caused by using less memory, the memory of 5 fields can be implemented in the same cycle as in the prior art.

As described above, the method and apparatus for converting the frame rate in the field unit for the deinterlacing output of the present invention converts the frame rate in the field unit rather than the frame unit according to the prior art, thereby alleviating the unnaturalness of the motion caused by the frame rate converting operation. Provide effect. In addition, compared with the prior art, it is possible to implement a frame rate conversion operation using less memory.

Claims (6)

In the frame rate conversion method, (1) writing the interlaced scan signals input in the order of input to the field memory, and outputting the state of the field memory as a result; (2) identifying which area the write pointer is accessing according to the signal output in step (1); (3) determining a read area in which write and read pointers do not collide according to the verification result of step (2), and reading frame units to convert frame rates; And (4) A frame rate conversion method for deinterlacing output, comprising converting the interlaced signal read out from the field memory into a de-interlacing signal in step (3). The method of claim 1, wherein step (3) A method of converting a frame rate for deinterlacing output, wherein three fields (previous, present, and after) are simultaneously read for deinterlacing. The method of claim 2, wherein step (3) If the read is faster than the write, if it is determined that the read pointer collides with the write pointer, the frame rate conversion method, characterized in that for repeating one field. The method of claim 2, wherein step (3) If the read is slower than the write, frame rate conversion method characterized in that skipping of one field if it is determined that the read pointer collides with the write pointer. In the frame rate converter, A field memory in which input interlaced scanning signals are sequentially written; An input processor for outputting interlaced scan signals to the field memory, and outputting the result of the field memory; Before reading a new field from the field memory, the state of the field memory is input from the input processing unit to determine a possibility of collision between a write and a read pointer, and the frame rate is determined by repeating or skipping reading in units of fields according to the determination result. A memory lead unit for converting and outputting the converted memory output unit; And And a deinterlacing unit configured to perform deinterlacing using the field information output from the memory lead unit. The method of claim 5, wherein the memory lead portion If read is faster than write and read pointer collides with write pointer, it reads one field from field memory repeatedly, And determining that the frame rate is converted by reading one field from the field memory when the read is slower than the write and the read pointer collides with the write pointer.

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