TWI492866B - Video recording apparatus - Google Patents

Description

Image recording device

The present invention relates to an image recording apparatus.

In the conventional image recording device, the exposure is comprehensively adjusted according to the brightness value of the entire scene, but because of the influence of the high dynamic scene, the most important license plate information in the driving recorder may be unrecognizable because the brightness is too low, thereby causing Recording images is useless in the identification of car accidents, and this problem is especially noticeable at night.

However, if the license plate content is clearly recorded in the night scene, the brightness of the license plate is enhanced to a recognizable degree, which may cause the entire recorded scene to be overexposed and the traffic accident cannot be clearly seen.

In view of the above problems, the present proposal provides an image recording apparatus that addresses the aforementioned problems.

The image recording apparatus of the present invention comprises:

A camera unit, a search unit, an exposure decision unit, a processing unit, and a storage unit.

The camera unit is configured to capture a plurality of original images according to at least two exposure parameters; capture a first image according to the first exposure parameter, and capture a second image according to the second exposure parameter The image, wherein the exposure parameter refers to a combination of an aperture aperture, a shutter speed, and a gain value, and adjusting the exposure parameter means changing at least one of the three. A search unit performs a license plate image search based on at least the first image or the second image, and outputs a license plate position and a license plate size. An exposure determining unit determines a third exposure parameter of the first subsequent captured image according to the first image and a fourth exposure parameter of the second subsequent captured image according to the second image, wherein the second subsequent parameter The fourth exposure parameter of the image is determined based on the license plate position and size. A processing unit performs image processing on the first image and the second image respectively, and outputs a third image and a fourth image respectively through a certain format. a storage unit stores the third image and the fourth image, respectively.

The image recording device of the present invention further includes a tone-corresponding unit for improving brightness information of a dark portion of an input image for facilitating license plate search, and the tone correspondence unit comprises: a corresponding curve (curve) or A look-up table, wherein the search unit adjusts a first tone of the input image to a second tone according to the corresponding curve or the correspondence table, and then performs a license plate search.

The odd image of the original image is the first image, the even image is the second image, or the even image of the original image is the first image, and the odd image is the second image.

In the image recording apparatus of the present invention, the processing unit includes: a first image compression unit and a second image compression unit for compressing the third image and the fourth image, respectively.

The first image compression unit compresses the third image in a hard manner, and the second image compression unit compresses the fourth image in a soft body.

Among them, to adjust the exposure amount at least need to change the aperture aperture.

The second exposure parameter is based on a gain adjustment in the first exposure parameter and multiplied by the gain adjustment.

The search unit may perform a search for the license plate image in the vicinity of the designated position after a user selects a designated location.

The processing unit processes the third image with a third tone and the fourth image with a fourth tone.

The advantages and spirit of the present invention will be further understood from the following detailed description of the invention.

100‧‧‧ camera unit

201, 203‧‧‧ license plate image

300‧‧‧Exposure decision unit

301‧‧‧Switch unit

302‧‧‧Scene metering unit

303‧‧‧Search unit

304‧‧‧ License Plate Metering Unit

400‧‧‧Processing unit

501‧‧‧Video switching unit

502‧‧‧First video encoder

503‧‧‧Second video encoder

600‧‧‧ storage unit

601‧‧‧ third image

602‧‧‧ fourth image

31,33‧‧‧ Vehicle imagery

35,37‧‧‧ License Plate Image

95‧‧‧ first image

96‧‧‧Second image

98‧‧‧ odd banners

99‧‧‧ even banners

The first figure is a block diagram of an image recording apparatus of the present invention; the second figure is a schematic view of an embodiment of the third embodiment of the present invention; and the fourth figure is a schematic view of an embodiment.

The detailed features and advantages of the present invention are set forth in the Detailed Description of the Detailed Description of the <RTIgt; </ RTI> <RTIgt; </ RTI> </ RTI> </ RTI> <RTIgt; The objects and advantages associated with the present invention can be readily understood by those skilled in the art.

The image recording apparatus of the present invention will be described in detail below with reference to the drawings, and the same elements will be denoted by the same reference numerals.

Please refer to the first figure, which is a block diagram of an image recording apparatus of the present invention. In the first figure, the image recording device includes an image capturing unit 100, a searching unit 303, and a The exposure determining unit 300, a processing unit 400, and a storage unit 600.

The camera unit 100 includes a lens group, an aperture, an image sensor, an analog gain, a data output interface, and other necessary components (not shown).

The exposure decision unit 300 includes a switch unit 301, a scene light metering unit 302, a search unit 303, and a license plate metering unit 304.

The processing unit 400 includes a video switching unit 501, a first video encoder 502, and a second video encoder 503.

The camera unit 100 receives at least two exposure parameter controls to capture a plurality of original images, and the exposure parameters are combined by the aperture aperture, the shutter speed and the gain value, and the exposure amount is adjusted to at least change the aperture aperture and change at least one of the three; The camera unit 100 can simultaneously capture the odd frame 98 with the first exposure parameter and the even frame 99 with the second exposure parameter.

After capturing the odd-numbered amplitude 98 and the even-numbered amplitude 99, the image capturing unit 100 first subtracts the black level and after the digital gain is amplified, inputs the captured odd-numbered amplitude 98 and the even-numbered amplitude 99 into the exposure determining unit. 300. The odd-numbered frame 98 enters the scene metering unit 302 via the switching unit 301 to analyze the brightness of the scene, and determines a set of appropriate exposure parameters as the exposure parameters for capturing the next odd-numbered amplitude 98. The even-numbered frame 99 enters the search unit 303 via the switching unit 301 to search for the license plate image, and outputs all the license plate position and the license plate size information in the image. The search unit further includes a first-order corresponding unit for improving an input image. The brightness information of the dark part is used for the license plate search, and the tone corresponding unit includes: a curve or a look-up table, wherein the search unit inputs the image according to the corresponding curve or the corresponding table. The first-order tone is adjusted to a second-order tone, and then the license plate search is performed. then, Then, the card photometry unit 304 analyzes the brightness of the license plate image, and determines a set of appropriate exposure parameters according to the license plate position and the license plate size as the exposure parameter of the next even amplitude 99, so that the license plate image of the even frame 99 is compared. The license plate image of the odd-numbered frame 98 is clearer and easier to identify.

The processing unit 400 performs image processing on the odd-numbered frame 98 and the even-numbered frame 99 by using the first video encoder 502 and the second video encoder 503, respectively, and outputs a third image 601 and a fourth image 602 in a certain format. The processing unit 400 processes the third image with a third tone, and processes the fourth image with a fourth tone. Finally, the third image 601 and the fourth image 602 are respectively stored by the storage unit 600.

The processing unit 400 includes a first image compression unit and a second image compression unit, and compresses the third image and the fourth image, respectively. The first image compression unit compresses the third image in a hard manner, and the second image compression unit compresses the fourth image in a soft body. The second image compression unit can be implemented by the soft body method. When the license plate image is exposed correctly, the brighter area other than the license plate image may be overexposed, and the detailed information of the image is greatly reduced, so the calculation amount of compression is performed. It is also much lower, and the computing power of the soft corpuscle is sufficient. In order not to increase the cost of hardware, it should be implemented in soft rafts.

Incidentally, the adjustment of the exposure amount requires at least changing the aperture of the aperture, and the first preference for adjusting the exposure amount is to change the aperture of the aperture, because the aperture is increased, and the amount of light entering becomes large, and Adding noise helps to accidentally read the license plate when reading the image record.

In the image recording apparatus of the present invention, the first exposure parameter and the second exposure parameter, wherein the second preference for adjusting the exposure amount may be changing the exposure time. This is because The exposure time becomes longer, the amount of light entering becomes larger, and no noise is added, which helps the license plate interpretation when the image recording is accidentally occurred.

Furthermore, the aperture diameter, exposure time, and gain value of the aperture need to be matched with each other. Sometimes it is only necessary to adjust one of them, sometimes it is necessary to adjust two of them, and sometimes it is necessary to adjust the three. The prioritization of the above adjustments is conceptually the case. When it is actually applied, it is limited by the aperture aperture, frame rate and other factors, and the order of change is appropriately arranged.

In order to further clarify the technical features of the present invention, another embodiment will be further exemplified below, and the image recording apparatus is also disposed on the vehicle body as an example, but not limited thereto.

Please refer to the second, third and fourth figures together. In the second figure, the image recording apparatus includes an image capturing unit 100, a searching unit 303, an exposure determining unit 300, a processing unit 400, and a storage unit 600.

The camera unit 100 includes a lens group, an aperture, an image sensor, an analog gain, a data output interface, and other necessary components (not shown).

The exposure decision unit 300 includes a switch unit 301, a scene light metering unit 302, a search unit 303, and a license plate metering unit 304.

The processing unit 400 includes a video switching unit 501, a first video encoder 502, and a second video encoder 503.

The camera unit 100 receives at least two exposure parameter controls to capture a plurality of original images, and the exposure parameters are combined by the aperture aperture, the shutter speed and the gain value, and the exposure amount is adjusted to at least change the aperture aperture and change at least one of the three; The camera unit 100 can At the same time, the first image 95 is captured by the first exposure parameter, and the second image 96 is captured by the second exposure parameter.

After capturing the first image 95 and the second image 96, the camera unit 100 first offsets the black level, and after the digital gain is amplified, the captured first image 95 and the second image 96 are input to the exposure determining unit. 300. As shown in the third figure, the first image 95 enters the scene metering unit 302 via the switching unit 301 to analyze the brightness of the scene, and determines a set of appropriate exposure parameters to be used as an exposure parameter for capturing the next image of the first image. The vehicle images 31, 33 and the license plate images 35, 37 in the picture can be clearly presented. As shown in the fourth figure, the second image 96 enters the search unit 303 via the switching unit 301 to search for the license plate images 201 and 203, and outputs all license plate positions and license plate size information in the image, wherein the search unit further includes a first order. The corresponding unit is configured to improve the brightness information of the dark portion of an input image to facilitate the license plate search. The tone corresponding unit includes: a corresponding curve, wherein the search unit inputs a first image of the second image 96 according to the corresponding curve. The tone is adjusted to a second tone, and then the license plate search is performed. Then, the card photometry unit 304 analyzes the brightness of the license plate image, and determines a set of appropriate exposure parameters according to the license plate position and the license plate size to take the exposure parameter of the next frame of the second image 96, so that the second image 96 The numbers of the "license plate images" 201 and 203 are more clearly identifiable than the numbers of the "license plate images" 35 and 37 of the first image 95.

The processing unit 400 performs image processing on the first image 95 and the second image 96 by using the first video encoder 502 and the second video encoder 503, respectively, and outputs a third image 601 and a fourth image 602 in a certain format. The processing unit 400 processes the third image with a third tone, and processes the fourth image with a fourth tone, so that the license plate image 201, 203 of the fourth image is smaller than the license plate image of the third image 35, 37. The numbers are clearer and easier to identify. Finally, the third image 601 is stored by the storage unit 600 and The fourth image 602.

It is to be noted that the search unit of the image recording device can also search for the license plate image in the vicinity of the designated position after a user selects a designated position on the screen through a screen or a touch screen.

It can be seen that the image recording apparatus of the present invention can overcome the problem that the license plate is difficult to identify due to insufficient brightness, in particular, in the situation of driving at night, in addition to clearly recording the scene scene in the driving situation.

So far, the spirit of the present invention has been described, and the method of the present invention will be described in detail with reference to specific embodiments to enable those skilled in the art to obtain sufficient knowledge to implement.

While the foregoing description of the preferred embodiments of the invention, the embodiments of the invention The spirit and scope of the principles of the invention. It will be appreciated by those skilled in the art that the invention may be modified in many forms, structures, arrangements, proportions and components.

Therefore, the embodiments disclosed herein are to be considered as illustrative and not restrictive. The scope of the present invention is defined by the scope of the appended claims, and the legal equivalents thereof are not limited to the foregoing description.

100‧‧‧ camera unit

300‧‧‧Exposure decision unit

301‧‧‧Switch unit

302‧‧‧Scene metering unit

303‧‧‧Search unit

304‧‧‧ License Plate Metering Unit

400‧‧‧Processing unit

501‧‧‧Video switching unit

502‧‧‧First video encoder

503‧‧‧Second video encoder

600‧‧‧ storage unit

601‧‧‧ third image

602‧‧‧ fourth image

98‧‧‧ odd banners

99‧‧‧ even banners

Claims (8)

An image recording device includes: an image capturing unit, configured to capture a plurality of original images according to at least two exposure parameters; a first exposure parameter captures a first image, and a second exposure parameter captures a second image, Wherein, the exposure parameter refers to a combination of an aperture aperture, a shutter speed and a gain value, and adjusting the exposure parameter means changing at least one of the three, the odd image of the original image is the first image, and the even image is The second image, or the even image of the original image is the first image, and the odd image is the second image; a searching unit performs a license plate image search based on the first image or the second image, and outputs a license plate location And a license plate size; an exposure determining unit, respectively, determining, according to the first image, a third exposure parameter of the first subsequent captured image and a fourth exposure parameter determining a second subsequent captured image according to the second image The fourth exposure parameter of the second subsequent captured image is determined according to the location and size of the license plate; a processing unit respectively for the first image A second image with the image processing, outputs a certain format via a third image and a fourth image; a storage unit storing the third image, respectively with the fourth image. The image recording device of claim 1, wherein the searching unit further comprises a tone-corresponding unit for improving brightness information of a dark portion of an input image for facilitating image search of the license plate, the tone corresponding to The unit includes: a corresponding curve or a correspondence table, wherein the searching unit adjusts a first tone of the input image to a second tone according to the corresponding curve or the correspondence table, and performs the license plate image search. The image recording device of claim 1, wherein the processing unit comprises a first image compression unit and a second image compression unit, and compresses the third image and the fourth image, respectively. The image recording device of claim 3, wherein the first image compression unit compresses the third image in a hard manner, and the second image compression unit compresses the fourth image in a soft body manner. image. The image recording apparatus of claim 1, wherein adjusting the exposure parameter requires at least changing the aperture diameter. The image recording device of claim 1, wherein the second exposure parameter is multiplied by the gain adjustment according to a gain adjustment of the first exposure parameter. The image recording device of claim 1, wherein the search unit can perform the search of the license plate image in the vicinity of the designated position after a user selects a designated location. The image recording device of claim 1, wherein the third image is processed by a third tone, and the fourth image is processed by a fourth tone.