影像測量儀的測量誤差是指影像測量儀本身固有的誤差。引起的誤差的原因是多方面的，在儀器設(shè)計、制造和使用的各個階段都可能出現(xiàn)誤差，稱為測量儀的原理誤差、制造誤差和運行誤差。

   1.原理誤差。

   屬于影像測量儀的主要誤差有：CCD攝像機畸變引起的誤差和不同測量方法引起的誤差。相機的制造和工藝，入射光的折射誤差和CCD在通過各個透鏡時的位置誤差等。目標(biāo)像點和理論像點：徑向畸變、偏心畸變、薄棱鏡畸變等, 并且徑向畸變大，切向畸變和薄棱鏡畸變小，圖像中心區(qū)域畸變小，邊緣畸變大，使用優(yōu)質(zhì)鏡頭可以減少畸變誤差的影響，但在精密測量中需要考慮畸變的影響，對測量結(jié)果進行修正。

  不同測量方法引起的誤差主要是指不同圖像處理技術(shù)引起的識別和量化誤差。圖像的邊緣是圖像的基本特征，是圖像中物體輪廓或物體不同表面之間的邊界的反映。邊緣輪廓是人類識別物體形狀的重要因素。也是圖像處理中重要的處理對象。在圖像處理過程中，需要進行邊緣提取。在數(shù)字圖像處理技術(shù)中，邊緣提取的方法有很多種，使用的提取點也不同。這是一個不小的變化，因此會影響最終的測量結(jié)果。例如，在測量圓形工件的半徑和圓心時，當(dāng)圓的輪廓發(fā)生變化時，其半徑值和圓心位置也會隨之變化?？梢姡瑘D像處理算法在圖像處理過程中對儀器的測量精度有著非常重要的影響，是影像測量的重點。

   2.制造誤差。

  影像測量儀的制造誤差有：導(dǎo)向機構(gòu)產(chǎn)生的誤差、安裝誤差等。導(dǎo)向機構(gòu)產(chǎn)生的誤差主要是影像測量儀機構(gòu)誤差中的直線運動定位誤差。影像測量為正交坐標(biāo)系測量儀器。直角坐標(biāo)系測量儀有3個相互垂直的軸，X、Y和Z軸。有3個運動部件沿這三個軸運動，使CXIED2可以相對于被測工件做三維直線運動。 選擇高質(zhì)量的運動引導(dǎo)機構(gòu)可以減少此類錯誤圖像。安裝錯誤是主要當(dāng)測量平臺與CCD相機的運動差計算公式為如角度E時，根據(jù)幾何知識可以得到誤差計算公式，如果測量儀的測量平臺級性能和CCD相機的安裝都非常出色。它們之間的夾角都在015b以內(nèi)，誤差就會很小。

  3.運行誤差。

  影像測量儀的運行誤差有：測量環(huán)境和條件變化（如溫度變化、電壓波動、光照條件變化、機構(gòu)磨損等）引起的誤差和動態(tài)誤差。由于溫度放置關(guān)系和一些重要的特性參數(shù)發(fā)生了變化。從而影響儀器的精度，溫度的變化會影響成像測量。測量儀器上下光源燈的亮度導(dǎo)致系統(tǒng)照明不均勻，從而導(dǎo)致捕獲圖像邊緣出現(xiàn)陰影導(dǎo)致圖像邊緣提取誤差。磨損使影像測量儀的零件產(chǎn)生尺寸、形狀和位置誤差，配合間隙增大，降低了儀器工作精度的穩(wěn)定性。因此，改善測量操作條件可以有效降低此類誤差的影響。

The measurement error of image measuring instrument refers to the inherent error of image measuring instrument itself. The causes of the error are various, in the instrument design, manufacture and use of each stage may appear error, known as the principle of the measuring instrument error, manufacturing error and operation error.

1. Principle error.

The main errors of image measuring instrument are: CCD camera distortion error and error caused by different measurement methods. Camera manufacturing and technology, refraction error of incident light and CCD position error when passing through each lens. Image point target image point and theory: the radial distortion, eccentric distortion and thin prism distortion, etc., and radial distortion, tangential distortion and thin prism distortion is small, the image distortion center area is small, the edge distortion, using high quality lens can reduce the influence of the distortion error, but need to consider the effect of distortion in the precision measurement, the measurement results are corrected.

The errors caused by different measurement methods mainly refer to the recognition and quantization errors caused by different image processing techniques. The edge of an image is the basic feature of the image, which is the reflection of the contour of the object or the boundary between different surfaces of the object. Edge contour is an important factor for human to recognize the shape of objects. It is also an important object in image processing. In the process of image processing, edge extraction is needed. In digital image processing technology, there are many methods of edge extraction, and different extraction points are used. This is not a small change, so it affects the final measurement. For example, when measuring the radius and center of a circular workpiece, when the contour of the circle changes, its radius value and center position will also change. It can be seen that the image processing algorithm has a very important influence on the measurement accuracy of the instrument in the process of image processing, which is the focus of image measurement.

2. Manufacturing error.

The manufacturing errors of the image measuring instrument include the errors generated by the guiding mechanism and installation errors. The error produced by the guiding mechanism is mainly the linear motion positioning error in the mechanism error of the image measuring instrument. Image measurement is an orthogonal coordinate system measuring instrument. A cartesian coordinate system has three perpendicular axes, X, Y and Z. There are three moving parts moving along these three axes, so that CXIED2 can make three-dimensional linear motion with respect to the workpiece under test. Choosing a high quality motion guide can reduce such false images. Installation error is mainly when the calculation formula of motion difference between the measuring platform and CCD camera is such as Angle E, error calculation formula can be obtained according to geometric knowledge, if the measuring platform level performance of the measuring instrument and the installation of CCD camera are very good. They're all within 015B, so the error is going to be small.

3. Operation error.

The operating errors of the image measuring instrument include the errors and dynamic errors caused by the changes of measuring environment and conditions (such as temperature change, voltage fluctuation, illumination condition change, mechanism wear loss, etc.). Due to temperature placement and some important characteristic parameters have changed. Thus affecting the accuracy of the instrument, temperature changes will affect the imaging measurement. The brightness of the upper and lower light source of the measuring instrument leads to uneven illumination of the system, which leads to the shadow at the captured image edge and leads to the error of image edge extraction. Wear causes the size, shape and position error of the parts of the image measuring instrument, and increases the fit clearance, which reduces the stability of the instrument's working accuracy. Therefore, improving the measurement operating conditions can effectively reduce the impact of such errors.