TWI634792B - Projection image adjustment method and a projector - Google Patents

Abstract

The invention discloses a projection image adjustment method and a projector, and belongs to the technical field of image processing. The method comprises: step S1, acquiring a screen image by an image sensor; and step S2, at least one type of screen image. The parameter is compared with the corresponding image parameter of the original image saved in the projector; in step S3, based on the comparison result, the parameter difference between the image parameter of the screen image and the image parameter of the original image is determined: If the parameter difference value is included in the difference range, the process exits; in step S4, the projection parameter related to the projected original image in the projector is adjusted according to the parameter difference, and the next frame original image is adjusted according to the adjusted projection parameter. Projected onto the projection screen, and then returns to step S1. The above technical solution has the beneficial effects of eliminating the influence of the projection screen with the background color or different projection environments on the projected image, expanding the diversity of the projection screen selection, and improving the viewing experience of the user.

Description

Projection image adjustment method and projector

The present invention relates to the field of image processing technologies, and in particular, to a projection image adjustment method.

In the existing projection technology, it is usually required to project the screen as white, or a white-colored light-colored screen, so as to ensure the image quality of the projected image to the utmost. If the selected projection screen is not white, for example, the screen is yellow, red, green or other colors, or there is color ambient lighting effect, the image projected on the projection screen may be affected by the background color of the screen or ambient lighting. Like distortion, the projection deviation between the image seen by the user and the original image reduces the user's viewing experience and limits the variety of projection screen selection.

According to the problems existing in the prior art, a projection image adjustment method and a projector are provided, which aim to solve the problem that the projection image is distorted by the background color of the screen or the ambient color in the prior art.

In a preferred embodiment, the foregoing technical solution specifically includes:

A method for adjusting a projection image, wherein an image sensor is installed on the projector to acquire a screen image displayed on the corresponding projection screen; the method for adjusting the projection image specifically includes: step S1, The image sensor acquires the screen image of the current frame; in step S2, at least one type of image parameter of the screen image of the acquired current frame and a corresponding one frame original saved in the projector Corresponding said image parameters of the image are compared, and the comparison result is output; and in step S3, determining the image parameter of the screen image and the image of the original image according to the comparison result Parameter difference between parameters: if the parameter difference value is included in a preset difference range, exiting; step S4, according to the parameter difference value, relating to projecting the original picture in the projector The projection parameters of the image are adjusted, and the original image of the next frame is projected onto the corresponding projection screen according to the adjusted projection parameters, and then returns to the step S1.

Preferably, the projection image adjustment method, wherein the category of the image parameter comprises: an RGB color channel component parameter; and/or a gamma curve parameter; and/or a histogram parameter; and/or a signal ratio parameter; And/or color saturation parameters; and/or brightness parameters.

Preferably, the projection image adjustment method, in the step S3, determining according to the parameter difference corresponding to the at least one type of the image parameter, and pairing the projection according to at least one of the parameter difference values The parameters are adjusted.

Preferably, the projection image adjustment method is configured to respectively divide the screen image and the original image into a plurality of pixel blocks of equal size; in the step S3, each of the screen images is associated with each of the screens. Comparing the pixel blocks of the image with the corresponding pixel blocks of the original image to obtain the parameter difference value corresponding to each of the pixel blocks and outputting the step; the step S4 specifically includes: S41. Adjust, according to the parameter difference value, the projection parameter related to each of the pixel blocks that project the original image; and in step S42, combine the original image according to all the pixel blocks that are adjusted. The image is projected onto the projection screen, and then returns to the step S1.

Preferably, the projection image adjustment method, wherein the preset difference range is 0 in the step S3; in the step S3, determining the image parameter and the image of the screen image The parameter difference between the image parameters of the original image is described, and when the parameter difference is 0, the parameter is directly exited.

Preferably, the projection image adjustment method is applied to a digital light processing projection system.

A projector in which the above-described projection image adjustment method is applied.

The beneficial effects of the above technical solution are: providing a projection image adjustment method, which can eliminate the influence of the projection screen with the background color or different projection environments on the projection image, expand the diversity of the projection screen selection, and enhance the user's viewing experience. .

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without departing from the scope of the present invention are within the scope of the present invention.

It should be noted that the embodiments in the present invention and the features in the embodiments may be combined with each other without conflict.

The invention is further illustrated by the following figures and specific examples, but is not to be construed as limiting.

The latest projection technology, Digital Light Processor (DLP) projection technology, is a projection technology that enables digital information display. DLP projection technology uses Digital Micro-mirror Device (DMD) as a light valve imaging device, which can make the image gray level reach 256-1024, the color type reaches 2563-10243, and has the advantage of reflection. The total light efficiency of the imaging device is over 60%. However, DLP projection technology, including conventional cathode ray tube (CRT) projection technology and liquid crystal device (LCD) projection technology, has limitations on projection screen selection, that is, white or The approximation of a white, light-colored screen acts as a projection screen, and minimizes the effect of colored ambient light on the projected image to present a more realistic projected image to the user on the projection screen. The reason for the above limitation is that the projector itself does not automatically change the projected image according to the color of the screen. The projector is designed without considering the factors that affect the projected image by the color of the screen and/or the ambient color, so the projector cannot Respond promptly to the background color and/or ambient color of the screen.

In a preferred embodiment of the present invention, based on the above problems existing in the prior art, a technical solution of a projection image adjustment method is now provided.

In a preferred embodiment of the present invention, the projection image adjustment method is applied to a projector, and the premise is that an image sensor is disposed on the projector to collect a screen image projected by the projector on the projection screen. . Therefore, in a preferred embodiment of the invention, the orientation of the image sensor is consistent with the orientation of the projection lamp, both facing the projection screen.

In a preferred embodiment of the present invention, the image sensor does not change the image quality of the captured image during the acquisition process, that is, the screen image projected on the projection screen and the image sensor are collected. The screen image is consistent.

In a preferred embodiment of the present invention, as shown in FIG. 1 , the method for adjusting a projection image specifically includes: Step S1 , collecting a screen image of a current frame by using an image sensor; In the example, the image sensor collects each frame of the screen image and sends it to the projector in time.

Step S2 , comparing at least one type of image parameters of the collected screen image of the current frame with corresponding image parameters of a corresponding one frame of the original image saved in the projector, and outputting the comparison result; In a preferred embodiment, the categories of image parameters may include: RGB color channel component parameters; and/or gamma curve parameters; and/or histogram parameters; and/or signal ratio parameters; and/or color saturation parameters. ; and / or brightness parameters.

The RGB color channel component parameters may include an R channel component parameter, a G channel component parameter, and a B channel component parameter. In the subsequent parameter adjustment process, only the R channel component parameters, and/or the G channel component parameters, and/or the B channel component parameters may be determined and adjusted.

In other embodiments of the present invention, the image parameters may include other categories that can be characterized as image quality that are not listed above, and are not described herein again.

In a preferred embodiment of the invention, the so-called original image refers to a good image generated in the projector, that is, the original image is projected on a projection screen to form a screen image. In a preferred embodiment of the present invention, since the background color of the projection screen is not necessarily white, and the projection environment may be colored, the image quality of the screen image projected on the projection screen may be affected. Therefore, the above screen image is not necessarily the same as the original image, and there may be a deviation between the image parameter associated with the screen image and the corresponding image parameter associated with the original image. In the comparison results.

In a preferred embodiment of the present invention, only one or a plurality of types of image parameters as described above may be compared, and the number of categories of image parameters participating in the comparison may be previously fixed in the processor inside the projector, It can be set by the user according to different projection environments and/or different projection accuracy requirements.

Step S3 , determining , according to the comparison result, a parameter difference between the image parameter of the screen image and the image parameter of the original image: if the parameter difference is included in a preset difference range, exiting; In a preferred embodiment, the parameter difference refers to the difference between the image parameter associated with the screen image and the image parameter associated with the original image corresponding to the same type of image parameter. For example, corresponding to the R channel component parameter, the difference between the R channel component parameter associated with the screen image and the R channel component parameter associated with the original image.

In the preferred embodiment of the present invention, the range of difference refers to a range of image distortion that a predetermined user can accept, that is, an image distortion range that is difficult for the user to perceive by the naked eye. Specifically, if the parameter difference corresponding to one type of image parameter falls within the predetermined difference range, the difference between the screen image projected on the projection screen and the original image in the projector is relatively small, and the user passes It is difficult to distinguish with the naked eye. In a preferred embodiment of the present invention, the difference range may be set according to actual needs.

In a preferred embodiment of the present invention, when the parameter difference value is included in the preset difference range, the degree of distortion of the screen image is considered to be within an acceptable range, so that the projection parameter is not required. If you adjust accordingly, you can exit directly.

In a preferred embodiment of the present invention, the difference range can be set to 0, which means that only when the difference parameter is 0, the distortion degree of the screen image is considered to be acceptable, that is, only when the screen image is Exit directly when the original image is the same.

In a preferred embodiment of the present invention, in a comparison process, multiple types of image parameters may be selected, or multiple image parameters of a type of image parameters may be compared, for example: 1) RGB color channel component parameters may be selected. And the color saturation parameters are compared. The final comparison result is a composite value of the comparison result of the RGB color channel component parameter and the color saturation parameter, that is, only the parameter difference value related to the RGB color channel component parameter and the parameter difference related to the color saturation parameter are both falling. When it is within the above difference range, it is considered that no adjustment is needed at this time, and it is directly exited.

In a preferred embodiment of the present invention, a difference range can be set corresponding to a type of image parameter, and only the parameter difference values associated with each type of compared image parameter fall within the corresponding difference range. When you think that you don't need to make adjustments at this time, you can quit directly.

2) The R channel component parameter and the G channel component parameter in the RGB color channel component parameters can be selected, and only the parameter difference values related to the R channel component parameters and the parameter differences related to the G channel component parameters fall in correspondence. When the difference is within the range, it is considered that no adjustment is needed at this time and exits directly.

In a preferred embodiment of the present invention, the categories of image parameters participating in the comparison, and the subcategories in each category (for example, R channel component parameters in the RGB color channel component parameters, and/or G channel component parameters, and / or B channel component parameters) to meet the needs of different projection adjustment accuracy.

Step S4 , adjusting projection parameters related to the projected original image in the projector according to the parameter difference, and projecting the next frame original image onto the corresponding projection screen according to the adjusted projection parameters, and then returning to step S1.

In a preferred embodiment of the present invention, in the above step S4, comparing the R channel component parameters as an example, if the parameter difference analysis indicates that the screen image is related to the R channel component parameter is greater than the original image related to the R channel. The component parameter indicates that the R channel component parameter is increased after the original image is projected onto the screen image, and then the projection parameter in the projector (reducing the gain of the projection parameter related to the R channel parameter component) needs to be correspondingly reduced; Conversely, it is necessary to increase the projection parameters in the projector accordingly (increasing the gain of the projection parameters related to the R channel parameter components).

Correspondingly, in a preferred embodiment of the present invention, if image parameters of multiple classes or multiple subclasses are compared, the corresponding projection parameters are adjusted for different parameter differences.

In a preferred embodiment of the present invention, the projector projects the next frame image onto the projection screen according to the adjusted projection parameters, and returns to step S1 to continue to monitor the image distortion degree of the screen image until the image is distorted. The degree meets the demand.

In a preferred embodiment of the present invention, in order to improve the accuracy of the adjustment of the projected image, a plurality of pixel blocks of equal size are respectively divided for the screen image and the original image, for example, the screen is respectively displayed in units of 1*1. The image and the original image are divided into a plurality of pixel blocks. Then, in the above step S3, each pixel block connected to the screen image is compared with a corresponding pixel block related to the original image to obtain a parameter difference corresponding to each pixel block and output. In other words, each pixel block is treated as a separate image picture for independent comparison, and the parameter difference corresponding to each pixel block is output.

Therefore, in the preferred embodiment of the present invention, as shown in FIG. 2, the foregoing step S4 specifically includes:

Step S41 , adjusting projection parameters of each pixel block related to the projected original image according to the parameter difference value; and step S42 , combining the original image according to all the adjusted pixel blocks and projecting on the projection screen, and then returning to the step S1.

In a preferred embodiment of the present invention, according to the improvement of the image adjustment precision requirement, the process of comparing the original entire image is evolved into dividing the image into small pixel blocks and respectively comparing them, thereby greatly improving Image adjustment accuracy.

In a preferred embodiment of the present invention, the number of pixel blocks divided on an image can be determined according to the required image adjustment accuracy.

In a preferred embodiment of the present invention, the method for dividing a pixel block can cope with a situation in which a plurality of background colors are provided on one projection screen, and/or a projected image in a projection environment of ambient light having multiple colors. Image Quality.

In summary, in the technical solution of the present invention, the screen image of the current playback frame is collected and compared with the original image of the corresponding frame in the projector to obtain the parameter difference between the corresponding image parameters. . The corresponding projection parameters in the projector are adjusted according to the parameter difference, and the adjusted projection parameters are used to continue to project the next frame image to the projection screen, and at the same time continue to monitor the image distortion degree of the next frame image. The above process loops back and forth until the image distortion degree of a certain frame of the screen image satisfies the demand (the parameter difference falls within the difference range). The above technical solution can make up for the problem that the image display quality cannot be changed for different projection environments in the prior art, can expand the diversity of the projection screen selection, improve the stability of the image quality of the projected image, and thereby enhance the user's viewing experience. .

In a preferred embodiment of the present invention, the above-described projection image adjustment method can be applied to the above DLP projection system. Similarly, in other embodiments of the present invention, the above-described projection image adjustment method can also be applied to other projection systems such as a CRT projection system or an LCD projection system.

In a preferred embodiment of the present invention, there is also provided a projector in which the above-described projection image adjustment method is employed.

The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the embodiments and the scope of the present invention, and those skilled in the art should be able to Alternatives and obvious variations are intended to be included within the scope of the invention.

S1-S4‧‧‧ steps
S41-S42‧‧‧Steps

1 is a flow chart showing a method of adjusting a projection image in a preferred embodiment of the present invention. 2 is a flow chart showing a method for adjusting a projection image in a preferred embodiment of the present invention.

Claims (6)

A method for adjusting a projection image, wherein an image sensor is installed on the projector to obtain a screen image displayed on the corresponding projection screen; the method for adjusting the projection image specifically includes: step S1, passing the image The sensor acquires the screen image of the current frame; and in step S2, the at least one type of the screen image of the acquired current frame is associated with image parameters of color and/or brightness and is saved in the projector Comparing the corresponding image parameters of the corresponding one frame of the original image, and outputting the comparison result, the category of the image parameter includes one or any combination of the following: RGB color channel component parameter, gamma curve parameter And a signal-to-noise ratio parameter; step S3, determining, according to the comparison result, a parameter difference between the image parameter of the screen image and the image parameter of the original image: if the parameter The difference value is included in a preset difference range, and then exits; the screen image and the original image are respectively divided into a plurality of pixel blocks of equal size; in the step S3, each is associated with each Place Comparing the pixel blocks of the screen image with the corresponding pixel blocks associated with the original image to obtain the parameter difference value corresponding to each of the pixel blocks and outputting; step S4, according to the The parameter difference adjusts a projection parameter in the projector that is related to the projection of the original image, and projects the original image of the next frame onto the corresponding projection screen according to the adjusted projection parameter Then, return to the step S1. The projection image adjustment method according to claim 1, wherein the image parameter category further includes: a color saturation parameter; and/or a brightness parameter; the type of the image parameter is pre-cured inside the projector Processor or by The user can set according to different projection environments and/or different projection accuracy requirements. The method for adjusting a projection image according to claim 1, wherein in the step S3, determining according to the parameter difference corresponding to the at least one type of the image parameter, and according to at least one parameter difference corresponding to the parameter The projection parameters are adjusted. The method for adjusting a projection image according to claim 3, wherein the step S4 specifically includes: step S41, according to the parameter difference value, for each of the pixel blocks related to the projection of the original image. The projection parameters are adjusted; in step S42, the original image is combined according to all the pixel blocks that have been adjusted and projected on the projection screen, and then returns to the step S1. The projection image adjustment method according to claim 4, wherein the preset difference range is 0 in the step S3; in the step S3, determining the image of the screen image. The parameter difference between the parameter and the image parameter of the original image, and when the parameter difference is 0, exits directly. The projection image adjustment method according to claim 5 of the patent application is applied to a digital light processing projection system.