Improved image enhancement method based on block matching and recovery and combined trilateral steering filtering

A technology of guided filtering and image enhancement, applied in the field of image processing, can solve the problems of poor visual effect, poor preservation of structural information, loss of structural information, etc., to achieve the effect of removing pseudo-texture and noise, and achieving good visual effect.

A technology of guided filtering and image enhancement, applied in the field of image processing, can solve the problems of poor visual effect, poor preservation of structural information, loss of structural information, etc., to achieve the effect of removing pseudo-texture and noise, and achieving good visual effect.

CN106485672AInactive Publication Date: 2017-03-08XIDIAN UNIV

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  • Improved image enhancement method based on block matching and recovery and combined trilateral steering filtering
  • Improved image enhancement method based on block matching and recovery and combined trilateral steering filtering
  • Improved image enhancement method based on block matching and recovery and combined trilateral steering filtering

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0040] see figure 1 , the improved block matching repair of the present invention and joint trilateral guided filter image enhancement method, the enhancement process includes the following steps:

[0041] (1) Input image: input the original depth image collected and save it as a grayscale image, see image 3 . According to the Kinect image acquisition mechanism, the region formed by pixels with invalid pixel values ​​is an unknown region, and the remaining pixels, that is, the region formed by valid pixel values, is a known region. In this embodiment, the depth image is saved as 8 bits Grayscale image, so the pixel value of the invalid pixel is 0, and the area formed by the pixels whose pixel value is not 0 is the known area.

[0042] (2) Original image preprocessing: For the collected original depth image, use the morphological closing operation to perform preprocessing to remove the random depth missing points existing in the original image; see image 3 , the pixels wit...

Embodiment 2

[0053] Improved block matching repair and joint trilateral guided filtering image enhancement method are the same as embodiment 1, wherein the block matching priority estimation function P described in step (4):

[0054] The block matching priority estimation function P(p) of each pixel point p is defined as follows:

[0055] P(p)=C(p)D(p)L(p) (1)

[0056] Among them, C(p) represents the confidence of point p, that is, the proportion of known pixels in the neighborhood centered on p. The larger the ratio, the greater the number of known pixels in the pixel block centered on p. , that is, the more known information used to predict the pixel value of an unknown pixel, the more accurate the prediction result; D(p) represents the data item of point p, ensuring that the block close to the normal direction is repaired earlier; L(p) represents The level set distance factor is defined by the diffusion time function, thus ensuring that the closer the pixel is to the boundary of the un...

Embodiment 3

[0071] Improved block matching repair and joint trilateral guided filtering image enhancement method are the same as embodiment 1-2, wherein the joint trilateral guided filtering method described in step (9):

[0072] The filtering model of the joint trilateral guided filtering method is defined as follows:

[0073]

[0074] Among them, ω p As a normalization factor, the weighted sum of each factor is guaranteed to be 1, defined as shown in formula (8); JiontTF[I] pIndicates the result obtained by filtering the pixel block I centered on p by using joint trilateral guided filtering, I is the pixel block to be repaired, and I q is the intensity value of pixel point q, s is the neighborhood centered on p; parameter σ s is the size of the Gaussian kernel in the spatial domain, Computes the Gaussian weights in the spatial domain, which, like ordinary Gaussian filters, decrease as the spatial distance between p and q increases; I cp and I cq are the pixel values ​​of pixel ...

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Abstract

The invention discloses an improved image enhancement method based on block matching and recovery and combined trilateral steering filtering. With the method, removing of lots of holes and severe noises in a collected depth image is realized. The method comprises: pretreatment of an original image is carried out; a to-be-recovered unknown region in the image after pretreatment is marked; a pixel point priority level is calculated; a to-be-recovered block is selected; an optimal matching block is searched; recovering is carried out; determination is carried out; the image is processed by using combined trilateral steering filtering; and image enhancement processing is ended and a result is outputted. According to the method provided by the invention, with introduction of a horizontal set distance factor and a diffusion time function, a block-matching-based image recovery sequence is improved and a structural hole is filled; and on the basis of the combined trilateral steering filtering, a pseudo texture generated by recovering and lots of original noises are removed. In terms of a visual effect and a quantitative analysis, the texture structure of the original image can be kept well for the image after enhancement processing and noise information in the image is removed, so that the image distortion degree is low.

Description

technical field [0001] The invention belongs to the technical field of image processing, mainly relates to depth image enhancement, and specifically provides an improved image enhancement method of block matching repair and joint trilateral guide filtering, which can be used for hole filling and noise removal of depth images collected by Kinect and the like. Background technique [0002] In recent years, the cheapness of depth image acquisition equipment has provided the possibility for the acquisition and use of depth information, and also brought opportunities for the further development of applications involving depth information in robotics, especially in map construction, path planning, and environmental perception. etc., rely heavily on the effective use of depth information. [0003] However, as one of the inexpensive depth information collection devices, Kinect mainly relies on parallax images and triangulation principles to obtain depth information in the scene, so ...

Claims

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Application Information

Patent Timeline
08 Mar 2017
Publication
CN106485672A
IPC
G06T5/00
CPC
G06T2207/20036; G06T5/77; G06T5/70
Inventors
宋娟; 张亮