JPS618758A - Picture recording and reproducing device - Google Patents

Abstract

PURPOSE:To search efficiently a desired picture part in animations in a high speed by detecting the magnitude of a change with time between individual frame pictures of animations and controlling variably the recording or reproducing speed of animations in accordance with the detection result. CONSTITUTION:Picture element data fk (i, j) from a picture reproducing part 1 is inputted to an inter-picture variation detecting part 3, and a frame start circuit 11 detects the start timing of each frame (k). An absolute difference value detecting circuit 13 calculates an absolute difference value Fk (i, j) between picture element data of the frame (k) and data of the just proceding frame which is delayed in a delay circuit 13 by a time corresponding to one frame, and an accumulating circuit 14 accumulates the result in one frame. This value Sk is compared with prescribed thresholds A1-An by a comparator 15, and the magnitude of the variation is latched in a latch circuit 16 at the frame switching timing by the output of the circuit 11 and is inputted as reproducing speed variable control information to the picture reproducing part 1 through a D/A converter 17, and pictures are reproduced in a speed corresponding to the change of pictures, and the reproducing time of the whole of pictures is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image recording and reproducing device that can facilitate searching for a specific frame image in a moving image, for example.

[Technical background of the invention and its problems]

Recently, moving images recorded on a video tape recorder (VTR) are frequently played back at high speed to search for a desired frame image portion. In this case, in conventional VTRs, each frame image of several consecutive frames in the moving image is partially extracted depending on the playback speed, and these partial frame images are connected to form one frame. I am trying to combine images and display them. For this reason, the quality of the reproduced image was very poor.

In addition, when frame images with little change continue, the content of the high-speed reproduction image can be determined relatively well, but when frame images with large changes continue, the image synthesized and displayed as described above is There was a problem in that the contents were extremely difficult to distinguish. Moreover, even though the moving image contains parts with large changes and parts with little change between frame images, it is played back at a constant speed, making it easy to search for the desired image part. It was inefficient to do so.

[Purpose of the invention]

The present invention has been made in consideration of the above circumstances, and its purpose is to quickly display a desired image portion of a moving image recorded by a VTR, for example, while ensuring the quality of the displayed image. It is an object of the present invention to provide a highly practical image recording and reproducing device that can perform searches efficiently.

[Summary of the invention]

The present invention detects the magnitude of temporal change between frame images of a moving image, and variably controls the recording or reproduction speed of the moving image, for example, in a VTR, in accordance with the detection result. For example, by variably controlling the playback speed of the VTR and displaying a moving image, the frame images are selected and displayed according to the detection result of the magnitude of temporal change between each frame image of the moving image. This is to ensure the quality of the displayed image.

The playback speed of the moving image is variable controlled, for example by increasing the playback speed when the temporal change between frame images is small and slowing down the playback speed when the temporal change between the frame images is large. Further, the recording speed of the moving image is variable controlled by slowing the recording speed when the temporal change between frame images is small and increasing the recording speed when the temporal change between the frame images is large. It was designed to do so.

〔Effect of the invention〕

Thus, according to the present invention, the reproduction speed or recording speed is varied according to the magnitude of temporal change between frame images of the moving image to be reproduced or the moving image to be recorded. Images that are recorded at a controlled recording speed and then played back at a normal constant speed are played back at approximately equal time intervals, mainly at large switching parts of frame images that are characteristic changing points of the moving image. becomes. In other words, in a series of moving images, parts with large changes between frame images can be efficiently reproduced (and as images of high quality).

In particular, according to the magnitude of m quantitative changes between frame images,
By switching the displayed image, so-called flickering of the displayed image is eliminated, and it becomes possible to display the image like a still image. Therefore, there are great practical advantages, such as the ability to quickly search for a desired image portion in a moving image.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment, and shows an example in which a moving image recorded on a VTR or the like is played back at high speed.

A reproduced moving image reproduced by an image reproduction section 1 such as a VTR is displayed as an image on an image display section 2 consisting of a TV receiver or the like. The image reproduction unit 1 has a configuration in which the reproduction speed is variably controlled during high-speed reproduction,
The playback speed control is performed based on the output of the inter-image variation detecting section 3.

The inter-image variation detection section 3 is configured, for example, as shown in FIG. 2, and sequentially detects the temporal variation between each frame image of a reproduced moving image. That is, the pixel data of pixel (i, j) in frame h of the moving image reproduced by the image reproduction section 1 is expressed as fk (i, j).
Then, the time series of the pixel data is sequentially input to the inter-image variation detection section 3. The frame start detection circuit 11 in the detection section 3 detects the start timing of each frame from the moving image data inputted from the image reproduction section 1. The pixel data 1 is then input to the one frame delay circuit 12 and delayed for one frame time. The absolute difference value detection circuit 13 detects the pixel data of the input frame as described above and the pixel data of the frame (k-1) inputted one frame before and delayed by one frame time in the delay circuit 13. The absolute difference value with F
k(i,j) as Fk(i,j)−l fk(
i, j)-f k-1(i, j) l. The cumulative addition circuit 14 calculates the absolute difference value Fk (i,
j ) over one frame and outputs the cumulative addition value 5k Sk=Σ Fk (i, j ). That is, the cumulative addition circuit 14 is cleared by the frame start detection circuit 11 at the start of the frame, and for the image in the frame,
The amount of temporal variation (cumulative addition value) Sk between frame images is detected as the sum of the absolute difference values of each pixel data with the corresponding pixel of the image one frame before.

This temporal variation 1iSk is applied to a comparator circuit 15 to obtain a predetermined equivalent value A1. A2. ~An, and the magnitude of the variation is determined. This comparison circuit 15
Information on the magnitude of the variation determined by is latched in the latch circuit 16 at each frame switching timing upon receiving the output of the frame start detection circuit 11, and
It is outputted as reproduction speed variable control information for the image reproduction section 1 via the /A converter 17.

This reproduction speed variable control information sets the image reproduction speed of the image reproduction section 1 to be slow when the temporal variation between the frame images is large, and when the temporal variation between the frame images is small, the This information is given as information for setting the image playback speed of the playback unit 1 to be faster. According to such playback speed variable control information, the image playback speed from the VTR is controlled, so that parts where there is little variation between frame images are played back at high speed, and parts where there is a lot of variation between frame images are played back at a relatively low speed. will be held. Therefore, the playback speed is controlled according to changes in frame images in a series of moving images, reducing the overall playback time and effectively playing back images that accurately capture the point. It becomes possible to do so. Moreover, the playback speed is controlled according to the temporal variation l between frame images.

It is also possible to ensure the quality of the reproduced image to some extent.

Note that when controlling the image playback speed in this manner, it is preferable to also control the image display according to the playback speed.

For example, as shown in FIG. 3, two frame image memories 21.22 are provided in parallel in the image display unit 2, and the frame image memories 21.22 are
What is necessary is to alternately write and read the reproduced image to and from the replay image.

Then, the frame images read out in the form of still images from each of the frame image memories 21 and 22 may be supplied to the display 25 for image display.

Furthermore, the switching control of each of the selectors 23 and 24 may be performed in accordance with the magnitude of the variation (2) detected by the inter-image variation detecting section 3. In other words, the comparison circuit 15
Each of the selectors 23.
What is necessary is to control the switching of 24.

In this way, each time a point in time when the amount of variation between frame images is large is detected, the data of that frame image is alternately input to one of the frame image memories 21 and 22. Then, from the other frame image memory that is not used for writing frame images, the frame image stored therein is read out as a still image and displayed on the display 25. When the next fluctuation point is detected, the reverse process is performed in the same way. Therefore, each time a portion with a large amount of variation between frame images is detected, a frame image that has changed significantly due to this is displayed on the display 25. Therefore,
In conjunction with the control of the image playback speed, the display 2
5, characteristic frame images of the moving image are displayed as samples one after another.

Thus, if display control is performed on the reproduced image as described above, the frame images that are switched and controlled for each part of the frame with a large amount of change in the reproduced video image are displayed one after another like a still image, so that The displayed image effectively shows the characteristics of the image information and is of high quality. Therefore, it becomes possible to effectively search for a desired image portion in the moving image using this displayed image.

By the way, the above explanation is an example of the case where a moving image is played back from a VTR, but it can be similarly applied to the case where a moving image is recorded on a VTR. FIG. 4 shows an example thereof. For example, an image input unit 5 consisting of a TV camera
is inputting a normal video image. This input video image is
The image is recorded on the image recording section 6, which is a VTR. The recording speed of the moving image by the image recording section 6 is variably controlled in accordance with the amount of temporal variation between frame images. The image variation detecting section 7 is configured similarly to that shown in FIG. 2 described above, and sequentially detects the temporal variation between each frame image of the input image.

Therefore, the inter-image variation detecting unit 7 controls the image recording speed in the image recording unit 6 at high speed when the inter-frame variation of the input moving image is large, and when the inter-frame variation is small, In this case, the image recording speed is controlled to be low. As a result, image information with a small amount of inter-frame variation is equivalently time-compressed and recorded, and image information with a large amount of inter-frame variation is equivalently time-expanded and recorded. In other words, when a moving image recorded under the above recording speed control is played back at a constant speed, the parts where there are large fluctuations between frames are
They will be played back almost evenly distributed over time.

Therefore, even when using a VTR that does not have a playback speed control function, if a moving image recorded as described above is played back, frame images indicating characteristic information of the moving image can be efficiently reproduced and displayed. This makes it possible to achieve the same effects as in the previous embodiment.

As described above, according to the present invention, the playback speed or image recording speed of an image is variably controlled depending on the amount of image variation between frames of a moving image. Frame images representing information can be efficiently displayed at approximately constant intervals in time. Therefore, great practical effects can be obtained, such as being able to efficiently search for a desired image portion in a moving image.

Note that the present invention is not limited to the above-described embodiments. For example, the thickness of the variation between frame images ('S) may be detected based on changes in acoustic information related to the moving image, that is, sounds, music, etc. that are separated from the moving image. , or the control range of the playback speed may be set according to the moving image.The detection level of the frame image memory switching control in the image display section 2 may also be set as appropriate. The device of the invention calculates the amount of variation between a preset image (or audio) and an image (or audio) that is input sequentially in time, and when the amount of variation is small, that is, the set image (or audio) is ) when it matches or is similar to
It can also be used for searches that stop the playback. In short, the present invention can be implemented with various modifications without departing from the gist thereof.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a device according to an embodiment of the present invention, FIG. 2 is a diagram showing an example of the configuration of an inter-image variation detection unit in the device according to the embodiment, and FIG. 3 is a configuration of an image display unit in the device according to the embodiment. FIG. 4 is a schematic diagram showing another embodiment of the present invention. 1... Image playback section, 2... Image display section, 3.7...
- Inter-image variation detection unit, 5... image input unit, 6...
Image recording unit, 11... Frame start detection circuit, 12.
...1 frame delay circuit, 13... Absolute difference value detection circuit, 14... Cumulative addition circuit, 15... Comparison circuit, 1
6...Latch circuit, 17...A/D converter, 21.
22...Frame image memory, 23°24...Selector, 25...Display. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 4

Claims (5)

[Claims] (1) An image recording and reproducing apparatus characterized by detecting the magnitude of temporal change between frame images of a moving image and variably controlling the recording or reproducing speed of the moving image according to the detection result. (2) A patent in which a moving image that is played back by variable control of the playback speed is displayed by selecting the frame images according to the detection result of the magnitude of temporal change between each frame image of the moving image. An image recording and reproducing apparatus according to claim 1. (3) Variable control of the playback speed of moving images is such that when the temporal change between frame images is small, the playback speed is increased, and when the temporal change between the frame images is large, the playback speed is slowed down. An image recording and reproducing apparatus according to claim 1. (4) Variable control of the recording speed of moving images slows down the recording speed when the temporal change between frame images is small, and increases the recording speed when the temporal change between the frame images is large. An image recording and reproducing apparatus according to claim 1. (5) The image according to claim 1, wherein the magnitude of the temporal change between frame images is detected using an image information difference between frame images or acoustic information related to a moving image. Recording and playback device.