WO2001011866A2

WO2001011866A2 - Method and apparatus for performing an automated inverse telecine process

Info

Publication number: WO2001011866A2
Application number: PCT/US1999/018295
Authority: WO
Inventors: Darren A. Giles
Original assignee: Terran Interactive
Priority date: 1999-08-11
Filing date: 1999-08-11
Publication date: 2001-02-15
Also published as: AU5479699A; WO2001011866A3

Abstract

A method and apparatus for performing an inverse telecine process is provided. For the method of the present invention, a computer system reads a series of frames in an input video sequence. The pixels in each frame are analyzed to determine if the frame is a composite frame produced by a prior telecine process. Frames that are determined to be composite frames are reconstructed, when practical, using their immediately preceding frames. Composite frames that cannot be reconstructed are transformed into interpolated frames. The computer system adds the reconstructed frames, along with the frames that did not need to be reconstructed, to an output video sequence.

Description

Method and Apparatus for Performing an Automated Inverse

Telecine Process

FIELD OF THE INVENTION The present invention relates generally to video processing systems. More

specifically, the present invention includes a method and apparatus for processing a

video sequence that automatically reconstructs the original frames from the output of

a preceding telecine process.

BACKGROUND OF THE INVENTION The film used to record and project motion pictures is divided into a sequence

of individual images known as frames. Video tape is encoded using a similar

sequence of frames. As a result, it might appear that converting between film and

video tape would be a simple process of transferring frames from the source media

to equivalent frames within the destination media. Unfortunately, film and video tape

are recorded using different frame rates. For film, the rate is typically twenty-four

frames for each second. Video tape encoded using the NTSC standard uses a rate

of approximately thirty frames per second. Video tape encoded using the PAL

standard uses a rate of approximately twenty-five frames per second.

The different frame rates used by film and video complicates the conversion

between the two types of media. Specifically, when converting from film to video

tape, each second of film must be expanded from twenty-four to thirty frames.

Effectively, an extra, or composite video frame must be made up or fabricated for

each four frames of film. When converting from video tape to film, each second of video tape must be reduced from thirty to twenty-four frames. This means that one

frame out of every five frames of video tape must be discarded.

The process of converting from film to video is known as telecine. Typical

telecine processes create composite frames using an interlacing method. The

interlacing method takes advantage of the fact that video frames are divided into an

odd field and an even field. The even field includes all of the even lines within the

video frame. The odd field includes all of the odd lines within the frame. An extra, or

composite frame is created by combining the odd field from one frame with the even

field from an adjacent second frame. The composite frame is intended to

approximate a midway point between frames and is inserted between the first and

second frames.

The frames added by the telecine process make recordings made on film

viewable in video formats. There are many cases, however, where it is desirable to

remove the frames added during the telecine process. One of these cases arises

when video data needs to be compressed. Compression is used where it is

necessary to reduce the number of bits used to digitally encode video data.

Compression increases the capacity of storage devices, such as optical disks.

Compression also increases the performance of video transmissions, such as

satellite or Internet transmissions. Unfortunately, the composite frames produced by

the telecine process tend to disrupt the compression process. This occurs because

the output frame rate is higher (resulting in a greater amount of data), and because

composite frames tend to be different than both their preceding and following

frames. These differences introduce additional discontinuities in the sequence of

frames. Video compression methods, such as MPEG, are most effective when applied to relatively continuous frame sequences. These compression methods

exhibit lower efficiencies when they are applied to sequences of frames that have

been processed through the telecine process.

The traditional method for removing composite frames requires an operator to

manually detect the first composite frame by searching through the sequence of

frames encoded on a video tape. The composite frame is then discarded. Each

following fifth frame may then be discarded as well. In practice, this method suffers

from at least two deficiencies. The first is the requirement that an operator manually

scan through frames looking for the initial composite frame. The second, and

potentially more serious, deficiency arises when composite frames are to be

removed from a video tape that has been edited after the telecine process. In these

cases, frames within the video tape may have been removed or added. This means

that composite frames may occur at rather random intervals and not every fifth

frame. The result is that the process of manually selecting the initial composite frame

may have to be repeated. If a video tape includes a large number of edits, the

manual selection process may become extremely time consuming or impractical.

As a result, it is clear that there is a need for a process that automatically

removes the composite frames generated by the telecine process. This is especially

important where the composite frames cannot be assumed to occur on a strictly

periodic basis, as the case of an edited video tape. SUMMARY OF THE INVENTION

An embodiment of the present invention provides a method and apparatus for

performing an inverse telecine process. The inverse telecine process automatically

detects and replaces composite frames created during a preceding telecine process.

For the method of the present invention, a computer system reads each of the

frames in a source video sequence. The computer system uses the frames to create

an output video sequence.

During this process, the computer system analyzes the pixels included in

each frame read from the source video sequence. If the pixels included in the even

field of a frame correspond to the adjacent pixels included in the odd field, the

computer system concludes that the frame is original. An original frame includes

pixels from only one image. Original frames are added, without modification, to the

destination video sequence.

If the pixels included in the even field of a frame do not correspond to their

adjacent pixels included in the odd field, the computer system concludes that the

frame is composite. A composite frame includes pixels from two distinct images and

is created during a telecine process. When a composite frame is detected, the

computer system attempts to reconstruct the composite frame to form an original

frame.

To reconstruct composite frames into original frames, the computer system

compares the pixels included in the composite frame to the pixels included in the

frame that precedes the composite frame in the source video sequence. If the pixels

included in the even field of the composite frame correspond to their adjacent pixels

included in the odd field of the preceding frame, the computer system reconstructs an original frame using the even field of the composite frame and the odd field of the

preceding frame. If the pixels included in the odd field of the composite frame

correspond to their adjacent pixels included in the even field of the preceding frame,

the computer system reconstructs an original frame using the odd field of the

composite frame and the even field of the preceding frame. The computer system

adds reconstructed frames to the destination video sequence.

The computer system creates interpolated frames for composite frames that

cannot be reconstructed. The computer system creates interpolated frames by

applying an interpolation function to the pixels included in the composite frames. The

computer system adds interpolated frame to the destination video sequence only if

they cannot be discarded without compromising the synchronization between the

source and destination video sequences.

The method of the present invention performs the inverse telecine process

using only a single pass and is self-adapting to a variety of different input and output

frame rates. The automatic detection of composite frames means that the method is

self-synchronizing and automatically adapts to discontinuities introduced during the

editing process.

Advantages of the invention will be set forth, in part, in the description that

follows and, in part, will be understood by those skilled in the art from the description

herein. The advantages of the invention will be realized and attained by means of

the elements and combinations particularly pointed out in the appended claims and

equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, that are incorporated in and constitute a part of

this specification, illustrate several embodiments of the invention and, together with

the description, serve to explain the principles of the invention.

Figure 1 is a block diagram of a host computer system shown as an

exemplary environment for an embodiment of the present invention.

Figure 2 is a block diagram of an inverse telecine process in accordance with

an embodiment of the present invention.

Figure 3 is a flow chart showing the steps associated with an inverse telecine

process as used by an embodiment of the present invention.

Figure 4a is a block diagram of a first original video frame as exemplary input

for an embodiment of the present invention.

Figure 4b is a block diagram of a second original video frame as exemplary

input for an embodiment of the present invention.

Figure 4c is a block diagram of a composite video frame as exemplary input

for an embodiment of the present invention.

Figure 5 is a flow chart showing the steps associated with a frame selection

method telecine process as used by an embodiment of the present invention.

Figure 6 is a detail showing a group of pixels in a video frame.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to preferred embodiments of the

invention, examples of which are illustrated in the accompanying drawings.

Wherever convenient, the same reference numbers will be used throughout the

drawings to refer to the same or like parts.

ENVIRONMENT

In Figure 1 , a computer system 100 is shown as a representative environment

for the present invention. Structurally, computer system 100 includes a processor, or

processors 102, and a memory 104. An input device 106 and an output device 108

are connected to processor 102 and memory 104. Input device 106 and output

device 108 represent a wide range of varying I/O devices such as disk drives,

keyboards, modems, network adapters, printers and displays. Each node 102 may

also includes a disk drive 110 of any suitable disk drive type (equivalently, disk drive

110 may be any non-volatile mass storage system such as "flash" memory).

INVERSE TELECINE PROCESS

An embodiment of the present invention includes a method and apparatus for

detects and replaces or discards composite frames created during a preceding

telecine process. As shown in Figure 2, a representative telecine process 202

accepts a source video sequence 204 as input and creates a destination video

sequence 206 as output. Source video sequence 204 and destination video

sequence 206 are video data encoded as sequences of individual frames. For the

purposes of the present invention, source video sequence 206 may be encoded

using any suitable video format, such as QUICKTIME, AVI, DV or MPEG, or. This means that source video sequence 206 may be taken from a wide range of different

sources, including computer networks, video tapes and optical disks. Destination

video sequence 206 may be created using any suitable video format (i.e.,

QUICKTIME, AVI, DV or MPEG). This allows destination video sequence 206 to be

created for a range of different destinations including, once again, computer

networks, video tapes and optical disks. For some embodiments, different video

formats will be used for source video sequence 204 and destination video sequence

206.

In Figure 3, a representative implementation of inverse telecine process 202

is shown as method 300. Method 300 includes a series of steps performed by

computer system 100 during transformation of source video sequence 204 to

destination video sequence 206. Method 300 begins with initialization step 302. In

step 302, computer system 100 performs any sub-steps that are required prior to

execution of the main steps of method 300. In particular, computer system 100

initializes a source timer and a destination timer. Computer system 100 uses the

source timer to track the number of seconds of source video sequence 204 that

have been consumed. Computer system 100 uses the destination timer to track the

number of seconds of destination video sequence 206 that have been produced. In

step 302, computer system 100 initializes both of these timers to zero.

In step 304, computer system 100 determines if the input of the inverse

telecine process is falling behind the output of the inverse telecine process. To make

this determination, computer system 100 compares the start time of the next frame

to be processed in source video sequence 204 (i.e., the source timer) to the start

time of the next frame to be added to output video sequence 206 (i.e., the destination timer). During the first execution of step 304, both of these timers are

zero and execution of method 300 automatically continues at step 312. In

subsequent executions, computer system 100 moves to step 306 if the destination

timer leads the source timer by a frame or more. In the alternative (i.e., if the

destination timer does not lead the source timer by a frame or more), computer

system 100 moves to step 312.

In the case where the input is falling behind the output, execution of method

300 continues at step 306. In step 306, computer system 100 skips over one of the

frames included in source video sequence 204. The skipped frame is discarded and

is not transferred to destination video sequence 206. The value of the source timer

is incremented by computer system 100 by an amount that is equal to the duration

of the skipped frame. This allows computer system 100 to advance through source

video sequence 204 to increase the synchronization between the source timer and

the destination timer.

Following execution of step 306, computer system 100 continues execution of

method 300 at step 308. In step 308, computer system 100 determines if there are

any unprocessed frames remaining in source video sequence 204. In the negative

case (where all frames have already been processed), computer system 100 ends

method 300 at step 310. Where there are remaining frames left to be processed,

computer system 100 continues method 300 with another iteration of step 304.

In the case where the input of the inverse telecine process is not falling

behind the output of the telecine process, computer system 100 continues execution

of method 300 at step 312. In step 312, computer system 100 retrieves a frame from

source video sequence 204. The frame retrieved during step 312 is one of two different types: original or composite. Original and composite frames are better

understood by reference to Figures 4a through 4c. In Figure 4a, a representative

frame is shown and generally designated 400a. Frame 400a includes a series of 486

lines. Each line has 420 pixels. The lines within each frame are divided into an even

frame and an odd frame. The even frame includes each even numbered line (i.e.,

lines 0, 2, 4, etc.) The odd frame includes each odd numbered line (i.e., lines 1 , 3, 5,

etc.)

A frame is original if the odd and even fields both contain pixel data from a

single image. For the purposes of this description, it is assumed that Figure 4a is

original and includes a single image of a solid rectangle. Frame 400b of Figure 4b

includes the same image of a rectangle. In the case of frame 400b, however, the

image of the rectangle has been shifted two pixels to the right. The shifted, solid

rectangle is the only image included in frame 400b. For this reason, frame 400b is

also an original frame.

A frame is composite if its odd and even fields contain pixel data from distinct

images. This is the case for frame 400c of Figure 4c. The even field of frame 400c

contains the same pixel data as the even field of 400a. The odd field of frame 400c

contains the same pixel data as the odd field of 400b. For this reason, frame 400c

contains pixels data from two distinct images, the solid rectangle of frame 400a and

the shifted, solid rectangle of Figure 4b. Composite frames result when video

sequence are transformed by a telecine process. Frame 400c is an intermediate

frame that was inserted between frames 400a and frame 400b to adapt source video

sequence 204 from a format having fewer frames per second (such as film) to a

format having more frames per second (such as video). The telecine process creates frame 400c using the even field of frame 400a and the odd field of frame

400b. Since frames 400a and 400b include different images, frame 400c contains

pixels data from two distinct images.

As mentioned, computer system 100 retrieves an original or a composite

frame from source video sequence 204 during step 312. When practical, the frame

retrieved in step 312 is original. In all other cases, the retrieved frame is composite.

An embodiment of the method used by computer system 100 to get a next frame

from source video sequence 204 is designated 500 in Figure 5. Method 500 may be

invoked as a subroutine or procedure. Alternately, method 500 may be included as

inline code within method 300.

Method 500 begins, symbolically, with placeholder 502. During each

invocation of method 500, computer system 100 reads a new frame from source

video sequence 204. This frame is referred to as the current frame. Before updating

the current frame, computer system 100 saves the old value (i.e., the frame read in

the preceding invocation of method 500). The saved frame is referred to as the

previous frame. In Figure 5, the process of saving the current frame as the previous

frame and reading a new frame to be the current frame are shown as steps 504 and

506, respectively. Both the previous frame and the current frame are stored in

memory buffers or otherwise positioned to allow the pixels within the frames to be

accessed. During step 506, computer system 100 increments the value of the

source timer by an amount that is equal to the duration of the frame read from

source video sequence 206.

In step 508, computer system 100 computes three values based on the pixels

included in the current frame and the pixels included in the previous frame. The first of these values measures the similarity between pixels included in the even field of

the current frame and adjacent pixels included in the odd field of the current frame.

For the sake of convenience this value is referred to in this document as: AC_EC₀ -

The second value calculated in step 508 measures the similarity between pixels

included in the even field of the current frame and adjacent pixels included in the

odd field of the previous frame. For the sake of convenience this value is referred to

in this document as: AC_EPo - The final value calculated in step 508 measures the

similarity between pixels included in the odd field of the current frame and adjacent

pixels included in the even field of the previous frame. For the sake of convenience

this value is referred to in this document as: AC₀ PE -

To compute AC_ECo computer system 100 selects a predetermined

percentage of the pixels of the even field of the current frame. For each selected

pixel, computer system 100 calculates a value that represents the degree of

similarity between the selected pixel and nearby pixels within the odd field of the

current frame. For one embodiment of the present invention, computer system 100

makes this calculation by comparing each selected pixel with four pixels that are

vertically aligned with the selected pixel. This is shown more clearly in Figure 6

where the selected pixel is shown at location x, y. Computer system 100 compares

this selected pixel with its two vertically aligned and adjacent neighbors. These

pixels are located at x, y + 1 and x, y - 1. Both of these pixels are included within the

odd field of the current frame (since the selected pixel is included within the even

frame). Computer system 100 also compares the selected pixel with the two pixels

that are vertically aligned and separated by one pixel from selected pixel. These

pixels are located at x, y + 2 and x, y - 2. Both of these pixels are included within the even field of the current frame (since the selected pixel is included within the even

frame).

Computer system 100 compares each selected pixel to the pixels above and

below the selected pixel using an equation of the form:

difference (x,y)

= ngb_diff ({x,y),(x,y+

+rgb_diff ((x,y),(x,y-fj

-rgb_diff ((x,yl(x,y+2))

-rgb_diff ((x,y),{x,y-2))

where rgb_diff (a,b) computes the difference between two pixels and b.

Preferably, but not necessarily, rgb_diff (a,b) computes the difference between

pixels a and b using the following equation:

tyb_diff (a,b) = V(ted(a) - red{b))² + (green(a) - green ))² + (blue(a) - blu j)²

rgb_diff (a,b) returns small values when pixels a and b are similar and

reaches zero when pixels a and b are equivalent. As a result, the function

difference (x,y) tends to be negative when evaluated within original frames that

include a single image. This follows because pixels within these frames tend to be

more similar to nearby pixels and less similar to pixels father away. This causes the

first two components of difference (x,y) (i.e., rgb_ diff ((x,y),(x,y + l)) and

rgb_diff ((x,y),(x,y-l))) to contribute a relatively small positive value while the

second two components (i.e., ngb_diff ((x,y),(x,y + 2)) and ngb_diff {(x,y),(x,y-2)))

contribute larger negative values. This situation is reversed for compositeframes that

include two images. In these cases, pixels tend to be more similar to pixels within

the same field. This means that pixels are more likely to resemble pixels two pixels

away (vertically) than they are to immediately adjacent pixels. This means that the

first two components of difference (x,y) contribute larger values than the second two

components making the overall value of difference positive.

To compute AC_EC₀ computer system 100 computes difference (x,y) for each

selected pixel in the current frame. AC_EC₀ is the sum of each computed value of

difference (x,y) . Negative values for AC_EC₀ indicate that pixels within the current

frame tend to be similar to their nearby pixels. This is expected for original frames that contain only a single image. Positive values for AC_EC₀ indicate that pixels

within the current frame tend to be different than their adjacent pixels but similar to

pixels in the same field. This is expected for composite frames that contain two

images.

Computer system 100 computes values for AC_EPo and AC₀P_E using the

same method used to compute A C_E C₀ - Before computing these values, however,

computer system constructs two frames. The first constructed frame includes the

even field from the current frame and the odd field from the previous frame. This

frame is referred to as C_E P₀ - The second constructed frame includes the odd field

from the current frame and the even field from the previous frame. This frame is

referred to as C₀ P_E . Computer system 100 repeats the method used to calculate

C_E C₀ using the first constructed frame (C_E P₀ ) to calculate AC_EP₀ - Computer

system 100 then repeats the method used to calculate A C_E C₀ using the second

constructed frame (C₀ Pε ) to calculate AC₀PE -

In step 510, computer system 100 compares A C_E C₀ , AC_EP₀ and AC₀P_E

with zero. If each of these values is greater than zero, computer system 100

concludes method 500 at step 512. In step 512 computer system 100 returns the

current frame and indicates that the returned frame is a composite frame.

In the alternative (i.e., where one of A C_E C₀ , AC_EP₀ and AC₀P_E is less

than zero) computer system 100 continues method 500 at step 514. In step 514,

computer system 100 determines if A C_E C₀ is less than AC_EP₀ and AC₀P - If so,

computer system 100 concludes method 500 at step 516. In step 516 computer system 100 returns the current frame and indicates that the returned frame is an

original frame.

In the alternative (i.e., where one of AC_EP₀ or AC₀P_E is less than A C_E C₀ )

computer system 100 continues method 500 at step 518. In step 518, computer

system 100 determines if AC_EP₀ is less than A C_E C₀ and AC₀Pε - If so, computer

system 100 concludes method 500 at step 520. In step 520 computer system 100

returns the C_E P₀ frame and indicates that the returned frame is an original frame.

The final alternative to the series of tests made in steps 510, 514 and 518 is

step 522. Computer system 100 reaches step 522 if AC₀P_E is less than A C_E C₀

and AC_EP₀. In step 522 computer system 100 returns the C₀ P_E frame and

indicates that the returned frame is an original frame.

In cases where method 500 returns an original frame (i.e., steps 516, 520 and

522), the returned frame may include one or both fields from the current frame.

Preferably, method 500 is configured so that the identity of these fields are tracked.

This allows computer system 100 to determine whether a particular field has been

previously used. Computer system 100 uses this information to avoid constructing

and returning frame (C_E P₀) or frame ( C₀ P_E ) where these frames would contain

previously used frames.

Following the invocation of method 500, computer system 100 continues

method 300 at step 314. In step 314, computer system 100 checks to see if method

500 returned an original or a composite frame. In the former case, computer system

continues at step 314 by adding the returned frame to destination video sequence

206. Computer system 100 also increments the destination timer by an amount

equal to the duration of the returned frame. Computer system 100 then continues method 300 at step 308 to determine if method 300 should continue to process

remaining frames in video sequence 204 or terminate at step 310.

In the case where computer system 100 determines in step 314 that the

frame is a composite frame, computer system 100 continues execution of method

300 at step 318. In step 318, computer system 100 determines if the input of the

telecine process has gotten ahead of the output of the inverse telecine process. To

make this determination, computer system 100 compares the start time of the

returned frame (i.e., the source timer) to the start time of the next frame to be added

to output video sequence 206 (i.e., the destination timer). Computer system 100

moves to step 320 if the source timer leads the destination timer by a frame or more.

In the alternative (i.e., if the source timer does not lead the destination timer by a

frame or more), computer system 100 moves to step 312.

In the case where input leads output, computer system 100 continues

execution of method 300 at step 320. In step 320, computer system 100 uses the

returned frame to create an interpolated frame. Each pixel (x, y) in the interpolated

frame is computed using a weighted average of the same pixel (x, y) in the returned

frame and two immediately adjacent pixels (x, y - 1) and (x, y + 1). For the purposes

of the present invention many different interpolation functions may be used. One

function that has been found to be particularly effective is:

interpolated frame (x, y) = 0.25 * subject frame (x, y -l)

+ 0.50 ^* subject frame (x, y) + 0.25^* subject frame (x, y + 1)

Computer system 100 adds the interpolated frame to destination video sequence

206. Computer system 100 increments the destination timer by an amount equal to

the duration of the interpolated frame. Computer system 100 then continues method 300 at step 308 to determine if method 300 should continue to process remaining

frames in video sequence 204 or terminate at step 310.

In the case where the input has not gotten ahead of the output, computer

system 100 continues method 300 at 322. This causes the returned frame to be

discarded, increasing the synchronization of input and output of the inverse telecine

process. In step 322, computer system 100 discards the returned frame. Computer

system 100 then continues execution of method 300 at step 324. In step 324,

computer system 100 determines if there are any unprocessed frames remaining in

source video sequence 204. In the negative case (where all frames have already

been processed), computer system 100 ends method 300 at step 310. Where there

are remaining frames left to be processed, computer system 100 continues method

300 with another iteration of step 312.

Other embodiments will be apparent to those skilled in the art from

consideration of the specification and practice of the invention disclosed herein. It is

intended that the specification and examples be considered as exemplary only, with

a true scope of the invention being indicated by the following claims and equivalents.

Claims

WHAT IS CLAIMED IS:

1. A method for performing an inverse telecine process that comprises

the steps, performed by a computer system, of:

retrieving a current frame and a preceding frame from a source video

sequence;

determining if the current frame is an original frame;

adding, where the current frame is an original frame, the current frame

to the destination video sequence;

determining, where the current frame is not an original frame, if an

original frame can be reconstructed; and

adding, where an original frame can be reconstructed, a reconstructed

frame to the destination video sequence.

2. A method as recited in claim 1 further comprising the step of: adding,

where an original frame cannot be reconstructed, an interpolated frame to the

destination video sequence

3. A method as recited in claim 1 wherein the step of determining if the

current frame is an original frame further comprises the steps of:

selecting a first pixel within the frame;

selecting a first group of one or more pixels;

selecting a second group of one or more pixels where the pixels

included in the second group are located farther from the selected pixel than

the pixels included in the first group; and

determining if the similarity between the second group of pixels and the

selected pixel exceeds the similarity between the first group of pixels and the

selected pixel.

4. A method as recited in claim 1 wherein the step of determining if an

original frame can be reconstructed further comprises the steps of:

creating a new frame, the new frame including a first field from the

current frame and a second field of the previous frame,

selecting a first pixel within the new frame;

selecting a first group of one or more pixels;

selecting a second group of one or more pixels where the pixels

included in the second group are located farther from the selected pixel than

the pixels included in the first group; and

determining if the similarity between the second group of pixels and the

selected pixel exceeds the similarity between the first group of pixels and the

selected pixel.

5. A computer program product comprising:

a computer usable medium having computer readable code embodied

therein for performing an inverse telecine process, the computer program

product comprising:

first computer readable program code devices configured to

cause a computer system to retrieve a current frame and a preceding

frame from a source video sequence;

second computer readable program code devices configured to

cause a computer system to determine if the current frame is an

original frame;

third computer readable program code devices configured to

cause a computer system to add, where the current frame is an

original frame, the current frame to the destination video sequence;

fourth computer readable program code devices configured to

cause a computer system to determine, where the current frame is not

an original frame, if an original frame can be reconstructed; and

fifth computer readable program code devices configured to

cause a computer system to add, where an original frame can be

reconstructed, a reconstructed frame to the destination video

sequence.

6. A computer program product as recited in claim 5 further comprising:

sixth computer readable program code devices configured to cause a computer

system to add, where an original frame cannot be reconstructed, an interpolated

frame to the destination video sequence

7. A computer program product as recited in claim 5 wherein the second

computer readable program code devices further comprise:

seventh computer readable program code devices configured to cause

a computer system to select a first pixel within the frame;

eighth computer readable program code devices configured to cause a

computer system to select a first group of one or more pixels;

ninth computer readable program code devices configured to cause a

computer system to select a second group of one or more pixels where the

pixels included in the second group are located farther from the selected pixel

than the pixels included in the first group; and

tenth computer readable program code devices configured to cause a

computer system to determine if the similarity between the second group of

pixels and the selected pixel exceeds the similarity between the first group of

pixels and the selected pixel.

8. A computer program product as recited in claim 5 wherein the fourth

computer readable program code devices further comprise:

eleventh computer readable program code devices configured to

cause a computer system to create a new frame, the new frame including a

first field from the current frame and a second field of the previous frame.

twelfth computer readable program code devices configured to cause a

computer system to select a first pixel within the new frame;

thirteenth computer readable program code devices configured to

cause a computer system to select a first group of one or more pixels;

fourteenth computer readable program code devices configured to

cause a computer system to select a second group of one or more pixels

where the pixels included in the second group are located farther from the

selected pixel than the pixels included in the first group; and

fifteenth computer readable program code devices configured to cause

a computer system to determine if the similarity between the second group of

pixels and the selected pixel exceeds the similarity between the first group of

pixels and the selected pixel.

9. An apparatus for performing an inverse telecine process, the

apparatus comprising:

means for retrieving a current frame and a preceding frame from a

source video sequence;

means for determining if the current frame is an original frame;

means for adding, where the current frame is an original frame, the

current frame to the destination video sequence;

means for determining, where the current frame is not an original

frame, if an original frame can be reconstructed; and

means for adding, where an original frame can be reconstructed, a

reconstructed frame to the destination video sequence.

10. An apparatus as recited in claim 9 further comprising: means for

adding, where an original frame cannot be reconstructed, an interpolated frame to

the destination video sequence

11. An apparatus as recited in claim 9 wherein the means for determining

if the current frame is an original frame further comprises:

means for selecting a first pixel within the frame;

means for selecting a first group of one or more pixels;

means for selecting a second group of one or more pixels where the

pixels included in the second group are located farther from the selected pixel

than the pixels included in the first group; and

means for determining if the similarity between the second group of

pixels and the selected pixel exceeds the similarity between the first group of

pixels and the selected pixel.

12. An apparatus as recited in claim 9 wherein the means for determining

if an original frame can be reconstructed further comprises:

means for creating a new frame, the new frame including a first field

from the current frame and a second field of the previous frame,

means for selecting a first pixel within the new frame;

means for selecting a first group of one or more pixels;

means for selecting a second group of one or more pixels where the

pixels included in the second group are located farther from the selected pixel

than the pixels included in the first group; and

determining if the similarity between the second group of pixels and the

selected pixel exceeds the similarity between the first group of pixels and the

selected pixel.

13. A method for determining if a frame is an original frame, the method

comprising the steps, performed by a computer system, of:

selecting a first pixel within the frame;

selecting a first group of one or more pixels;

selecting a second group of one or more pixels where the pixels

included in the second group are located farther from the selected pixel than

the pixels included in the first group; and

determining if the similarity between the second group of pixels and the

selected pixel exceeds the similarity between the first group of pixels and the

selected pixel.

14. A computer program product comprising:

a computer usable medium having computer readable code embodied

therein for determining if a frame is an original frame, the computer program

product comprising:

first computer readable program code devices configured to

cause a computer system to select a first pixel within the frame;

second computer readable program code devices configured to

cause a computer system to select a first group of one or more pixels;

third computer readable program code devices configured to

cause a computer system to select a second group of one or more

pixels where the pixels included in the second group are located

farther from the selected pixel than the pixels included in the first

group; and fourth computer readable program code devices configured to

cause a computer system to determine if the similarity between the

second group of pixels and the selected pixel exceeds the similarity

between the first group of pixels and the selected pixel.

15. An apparatus for determining if a frame is an original frame, the

method apparatus:

means for selecting a first pixel within the frame;

means for selecting a first group of one or more pixels;

means for selecting a second group of one or more pixels where the

pixels included in the second group are located farther from the selected pixel

than the pixels included in the first group; and

means for determining if the similarity between the second group of

pixels and the selected pixel exceeds the similarity between the first group of

pixels and the selected pixel.

16. A method for determining if an original frame can be reconstructed

from a first frame and a second frame, the method comprising the steps, performed

by a computer system, of:

constructing a third frame, the third frame including the even field from

the first frame and the odd field from the second frame;

selecting a first pixel within the third frame;

selecting a first group of one or more pixels;

selecting a second group of one or more pixels where the pixels

included in the second group are located farther from the selected pixel than

the pixels included in the first group; and

determining if the similarity between the second group of pixels and the

selected pixel exceeds the similarity between the first group of pixels and the

selected pixel.

17. A computer program product comprising:

a computer usable medium having computer readable code embodied therein

for determining if an original frame can be reconstructed from a first frame and a

second frame, the computer program product comprising:

first computer readable program code devices configured to cause a

computer system to construct a third frame, the third frame including the even

field from the first frame and the odd field from the second frame;

second computer readable program code devices configured to cause

a computer system to select a first pixel within the third frame;

third computer readable program code devices configured to cause a

computer system to select a first group of one or more pixels;

fourth computer readable program code devices configured to cause a

computer system to select a second group of one or more pixels where the

pixels included in the second group are located farther from the selected pixel

than the pixels included in the first group; and

fifth computer readable program code devices configured to cause a

computer system to determine if the similarity between the second group of

pixels and the selected pixel exceeds the similarity between the first group of

pixels and the selected pixel.

18. An apparatus for determining if an original frame can be reconstructed

from a first frame and a second frame, the apparatus comprising:

means for constructing a third frame, the third frame including the even

field from the first frame and the odd field from the second frame;

means for selecting a first pixel within the third frame;

means for selecting a first group of one or more pixels;

means for selecting a second group of one or more pixels where the

pixels included in the second group are located farther from the selected pixel

than the pixels included in the first group; and

means for determining if the similarity between the second group of

pixels and the selected pixel exceeds the similarity between the first group of

pixels and the selected pixel.