CN103162635A - Method for measuring diameter at breast height and tree height with camera - Google Patents

Abstract

The invention discloses a method that under the condition that a standing tree is not hewed down, the height of the standing tree, the diameter and the growing stock of any place of the standing tree are measured, and particularly, through the method of edge extraction of a forest in a digital photo, relevant data are measured. The stereoscopic photograph is applied to the forestry, the standing tree does not need to be hewed down, and the height of the standing tree, the diameter and the growing stock of any place of the standing tree can be measured, the new method is brought to the comprehensive analysis of growth conditions of trees, and the method enables forestry investigation to be more convenient and accurate. The method that the common camera is used for carrying out stereoscopic photograph tree measurement is simple and easy to operate, as long as people strictly operate according to technical requirements, the satisfactory investigation result can be obtained.

Description

A kind of method of using camera to measure the diameter of a cross-section of a tree trunk 1.3 meters above the ground and the height of tree

One, technical field

The invention relates in the situation that do not cut down the height that standing tree is measured standing tree, the diameter of any part and accumulating particularly proposes to record related data by the method for logarithmic code photograph forest Boundary Extraction.

Two, technical background

Da Caier had invented photography in 1839, was at first tested from photography having been carried out on ground in the air by Paris photographer Na Da in 1858 thereupon.In 19th-century, Frenchman Laussedat research application measurement camera is taken the ground photo and is come topographic mapping.The Pulfrich of Germany in 1901 and the Fourcado in South Africa in 1903 study respectively and have made stereocomparator, develop into terrestrial stereophotogrammetry.Wheatstne had invented stereoscope in 1838.Designed the First stereoautograph to Jena Zeiss factory in 1907, plotting method is further improved.Until the World War I, the development of close-range photogrammetry is almost the same with photogrammetric development.Be all both to take photo from land station, the method for use and instrument are also identical.Photogrammetricly mainly used airphoto to nineteen twenty.For using airphoto to develop stereoscopic plotting apparatus, these instruments are to recover the stereoscopic model in area being shot with optics, mechanical way simultaneously.These instruments are mainly used in topographic mapping, and the design of some instrument is also applicable to terrestrial photogrammetry and close-range photogrammetry.During from the nineteen twenty to the nineteen sixty, developed the stereo measurement camera that uses fixed base, the mapping system of this camera can be used for the aspects such as building, archaeology, engineering, mining and accident, and these are all the important development of close-range photogrammetry.Along with the development of close-shot photography measure technique, the aspect of its application is more and more extensive.Stereoscopic photograph is applied in forestry, need not cuts down standing tree, just can measure the height of standing tree, the diameter of any part and accumulating, for the upgrowth situations of multianalysis trees brings new method, for Forestry Investigation brought more convenient, more accurate method.

Method is simple to utilize ordinary digital camera to carry out the stereoscopic photograph assize, as long as in strict accordance with technical requirement operation, just can obtain satisfied investigation result, therefore, the stereoscopic photograph assize be a kind of efficiently, determination techniques accurately.

Three, summary of the invention

In order to overcome inefficient, the expensive situation of existing tree survey method, can conveniently measure trees, the purpose of this invention is to provide a kind of forest tree measurement method based on digital camera, it has overcome the shortcoming of classic method, for Forestry Investigation brought more convenient, more accurate method.

The object of the present invention is achieved like this:

By Cross ruler as the trees object of reference, take digital camera as instrument, the forest amount is photographed, use the method for Digital Image Processing, the logarithmic code photograph is directly processed, obtain the diameter of a cross-section of a tree trunk 1.3 meters above the ground, the height that related data calculates trees then and accumulate, concrete steps are as follows:

At first, settle Cross ruler in the plot in trees the place ahead, keep the level level, turn chi and forward 90 ° of directions to, adopt stadia method to record the camera settlement to the distance L of Cross ruler, real-time storage is to PDA;

Secondly, that utilizes ordinary digital camera to aim to erect on the plot turns chi, to carry out pan-shot perpendicular to the direction that turns chi, taking the photograph photograph is imported software, set up image plane side rectangular coordinate system o-xy according to photograph, then, with basic chi side in photograph, turn the chi direction and take direction and set up three-dimensional object space rectangular coordinate system O-XYZ, utilize coordinate on Cross ruler to obtain object coordinates and picture side's coordinate of corresponding 16 pixels on photograph, set up as square coordinate system and relationship model corresponding between object coordinates is

$\left\{\begin{array}{c}X=f(x,y)\\ Y=g(x,y)\\ Z=i(x,y)\end{array}\right..$

At last, utilize space intersection to calculate each point coordinate that single ebon to be measured does, obtain the height of tree and the diameter of a cross-section of a tree trunk 1.3 meters above the ground in conjunction with surveying data based equal proportion principle.

This invention is compared with existing method and is had the following advantages:

(1) method of photography assize is not subjected to the restriction of landform, and quick and easy;

(2) the ordinary digital camera low price, also can use when light and forest zone canopy density are larger, be more suitable for using in the forest zone, save time, reduced workload, improved work efficiency;

Use PDA storage and deal with data, greatly improved the automaticity of field work.

Four, description of drawings

The present invention is further described below in conjunction with accompanying drawing and example.

Fig. 1 is the Cross ruler structural representation, and Fig. 2 is that single wood measures schematic diagram.

Five, embodiment:

The ordinary digital camera forest tree measurement method is different from existing method, has done significant improvement, specifically:

measure the height of tree and the diameter of a cross-section of a tree trunk 1.3 meters above the ground take ordinary digital camera as instrument, at first select trees to be measured, settle Cross ruler in the plot in trees the place ahead, keep the level level, turn chi and forward 90 ° of directions to, adopt stadia method to record the camera settlement to the distance L of Cross ruler, that then utilizes ordinary digital camera to aim to erect on the plot turns chi, to carry out pan-shot perpendicular to the direction that turns chi, set up image plane side rectangular coordinate system o-xy according to photograph, then, with basic chi side in photograph, turn the chi direction and take direction and set up three-dimensional object space rectangular coordinate system O-XYZ, utilize coordinate on Cross ruler to obtain object coordinates and picture side's coordinate of corresponding 16 pixels on photograph, utilize ground coordinate and corresponding picpointed coordinate calculating 6 elements of exterior orientation separately at reference mark, calculate the baseline component with elements of exterior orientation, projection coefficient and the tested point coordinate in image space auxiliary coordinates separately, the terrestrial photogrammetry coordinate that utilizes at last space intersection to calculate point to be located is obtained the height of tree and the diameter of a cross-section of a tree trunk 1.3 meters above the ground in conjunction with surveying data based equal proportion principle.

According to the existing computing method of measuring, Cross ruler is inserted in the soil at bottom class center, keep the level level, turn chi and forward 90 ° of directions to, utilize ordinary digital camera at same plane to carry out twice pan-shot perpendicular to the diverse location that turns the chi direction, the spacing distance of twice shooting point is 10 meters, measures the distance B between two shooting points, two shooting points arrive the distance L of Cross ruler, utilize photograph to set up image plane side rectangular coordinate system x ₁oy ₁ix ₂oy ₂With basic chi direction in photograph, turn the chi direction and take direction and set up three-dimensional object space rectangular coordinate system, utilize coordinate on Cross ruler to obtain object coordinates and picture side's coordinate of corresponding 16 pixels on photograph, usage space forward intersection formula calculates the terrestrial photogrammetry coordinate of point to be located and obtains the height of tree in conjunction with surveying data based equal proportion principle, then calculates total counting wood strain tree Z in sample ground with angle gauge _hAt last according to digital-to-analogue

Calculate mean height, continue to measure, until survey complete sample district.

Claims (4)

1. method of using ordinary digital camera to measure the diameter of a cross-section of a tree trunk 1.3 meters above the ground and the height of tree, it is characterized in that: special Cross ruler is inserted in Dan Mu side or bottom class to be measured on request, use ordinary digital camera on request single wood or bottom class to be carried out pan-shot, with distance L and the record between tape measure photography place and special Cross ruler, import with taking the gained photograph photographic coordinate that process software obtains target to be measured, utilize special Cross ruler and distance L to obtain the coordinate relative to the earth of target to be measured, utilize coordinate to obtain mind and the height of tree of single wood or bottom class by modeling analysis and space intersection.

2. one kind based on the special Cross ruler described in claim 1, it is characterized in that: Cross ruler is by base, basic chi and turn chi and form.Base is that 15cm is high, and the cone of cone end radius 1.5cm is bored the extension that there is outside 2cm the bottom surface.Blade is by basic chi and turn chi and consist of, and the long 130cm of basic chi is connected with base, and there is level on the top.Turn the long 100cm of chi, can 90 ° of rotations, its axis of rotation utilizes exercisable screw to be fixed on the 80cm eminence of basic chi.

3. method based on the single wooden diameter of a cross-section of a tree trunk 1.3 meters above the ground of the measurement described in claim 1 and the height of tree, it is characterized in that: the Cross ruler described in claim 2 is inserted in the soil on the wooden side of list to be measured pedestal extend snap in ground till, keep the level level, turn chi and forward 90 ° of directions to, utilize ordinary digital camera to carry out pan-shot perpendicular to the direction that turns chi, measure shooting point to the distance of Cross ruler, photograph is imported process software, set up image plane side rectangular coordinate system xoy, with basic chi direction in photograph, turn the chi direction and take direction and set up three-dimensional object space rectangular coordinate system xyz, utilize coordinate on Cross ruler to obtain the object coordinates of corresponding 16 pixels on photograph, utilize software to set up as square coordinate system and relationship model corresponding between object coordinates is $\left\{\begin{array}{c}X=f(x,y)\\ Y=g(x,y)\\ Z=h(x,y)\end{array}\right..$ Resolve each point coordinate of trunk of Dan Mu to be measured by model, obtain the diameter of a cross-section of a tree trunk 1.3 meters above the ground to be measured and the height of tree.

4. one kind based on the measurement bottom class's diameter of a cross-section of a tree trunk 1.3 meters above the ground described in claim 1 and the method for the height of tree, it is characterized in that: Cross ruler is inserted in the soil at bottom class center pedestal extend snap in ground till, keep the level level, turn chi and forward 90 ° of directions to, utilize ordinary digital camera at same plane to carry out twice pan-shot perpendicular to the diverse location that turns the chi direction, the spacing distance of twice shooting point is no more than 10 meters, measures the distance L between two shooting points ₀, two shooting points arrive the distance L of Cross ruler ₁, L ₂Photograph is imported process software, set up image plane side rectangular coordinate system x ₁oy ₁And x ₂oy ₂, with basic chi direction in photograph, turn the chi direction and take direction and set up three-dimensional object space rectangular coordinate system X ₁Y ₁Z ₁And X ₂Y ₂Z ₂, utilize coordinate on Cross ruler to obtain object coordinates and picture side's coordinate of corresponding 16 pixels on photograph, usage space forward intersection formula $\left\{\begin{array}{c}x-x_0=-f\frac{a_1(X-X_5)+b_{1(Y-Y_5)+c_1(Z-Z_5)}}{a_3(X-X_5)+b_{3(Y-Y_5)+c_3(Z-Z_5)}}\\ y-y_0=-f\frac{a_2(X-X_5)+b_{2(Y-Y_5)+c_2(Z-Z_5)}}{a_3(X-X_5)+b_{3(Y-Y_5)+c_3(Z-Z_5)}}\end{array}\right.$ Resolve parameter, utilize in the parameter resolve and forward intersection Formula For Solving bottom class the coordinate of trunk point arbitrarily, utilize coordinate to find the solution the diameter of a cross-section of a tree trunk 1.3 meters above the ground to be measured and the height of tree.

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