Inter national J our nal of Electrical and Computer Engineering (IJECE) V ol. 10, No. 3, June 2020, pp. 2375 2382 ISSN: 2088-8708, DOI: 10.11591/ijece.v10i3.pp2375-2382 r 2375 De v elopment of ster eo matching algorithm based on sum of absolute RGB color differ ences and gradient matching Rostam Affendi Hamzah 1 , M. G. Y eou W ei 2 , N. Syahrim Nik Anwar 3 1 F akulti T eknologi K ejuruteraan Elektrik and Elektronik , Uni v ersiti T eknikal Malysia Melaka, Malaysi a 2,3 F akulti K ejuruteraan Elektrik, Uni v ersiti T eknikal Malysia Melaka, Malaysia Article Inf o Article history: Recei v ed Dec 19, 2017 Re vised Dec 11, 2019 Accepted Dec 18, 2019 K eyw ords: Bilateral filtering Computer vision Gradient matching Stereo matching Stereo vision ABSTRA CT This article presents local-based stereo matching algorithm whic h comprises a de v el- opment of an algorithm using block matching and tw o edge preserving filters in the frame w ork. Fundamentally , the matching process consists of se v eral stages which will produce the disparity or depth map. The problem and mos t challenging w ork for matching process is to get an accurate corresponding point between tw o images. Hence, this article proposes an algorithm for stereo matching using impro v ed Sum of Absolute RGB Dif ferences (SAD), gradient matching and edge preserving filters. It is Bilateral Filter (B F) to sur ge up the accurac y . The SAD and gradient matching will be im plemented at the first sta ge to get the preliminary corresponding result, then the BF w orks as an edge-preserving filter to rem o v e the noise from the first stage. The second BF is used at the last stage to impro v e final disparity map and increase the object boundaries. The e xperimental analysis and v alidation are using the Mid- dleb ury standard benchmarking e v aluation system. Based on the results, the proposed w ork is capable to increa se the accurac y and to preserv e the object edges. T o mak e the proposed w ork more reliable w ith current a v ailable methods, the quantitati v e measure- ment has been made to compare with other e xisting methods and it sho ws the proposed w ork in this article perform much better . Copyright c 2020 Insitute of Advanced Engineeering and Science . All rights r eserved. Corresponding A uthor: Rostam Af fendi Hamzah, F akulti T eknologi K ejuruteraan Elektrik and Elektronik, Uni v ersiti T eknikal Malaysia Melaka, Malaysia. Email: rostamaf fendi@utem.edu.my 1. INTR ODUCTION Computer vision is interdisciplinary fiel d that comprises methods for acquiring, proces sing and analyzing and image understanding from digital images or videos. It is artificial intelligence to mimic the human visual system. Stereo vision is a part of them and the process to get the information such as object detection, recognition and depth es timation is called as stereo matching. This process starts with corresponding from one point on reference image to another point on the tar get image. These images can be tw o or more. In this article, the images are using from the stereo camera input which is also kno wn as stereo images. The matching algorithm from the matching process produces disparity map. This map consists of depth information which is v aluable for man y applications such as virtual reality [1], 3D surf ace reconstruction [2], f ace recognition [3] and robotics automation [4-5]. The stereo baseline can be setup in a wide or short baseline [6] dista nce which depends on the applications. T o determine the range or distance estimation, the triangulation function is appli ed to each of the pix el on the disparity map. Therefore, to get an accu- rate result, the matching process requires com ple x and challenging solution for depth or distance estimation. It requires precise function on the propose frame w ork. Fundamentally , matching algorithm consists of multiple J ournal homepage: http://ijece .iaescor e .com/inde x.php/IJECE Evaluation Warning : The document was created with Spire.PDF for Python.
2376 r ISSN: 2088-8708 stages which w as proposed by Szeliski and Scharstein [7]. First stage, matching cost computes the preliminary matching point of stereo image. Second stage, the filtering is utilized to reduce the preliminary noise of the first stage. Then, disparity selection and optimization stage normalizes the disparity v alue each pix el on the image. Last stage is to refine the final result and also kno wn as disparity map post-processing step. In stereo matching de v elopment, there are tw o major approaches a v ailable in de v eloping the a lgorithm frame w ork. It is local methods as published in [8-10] and global method [11]. Mostly local methods use local properties or local contents using windo ws-based technique such as fix ed windo ws implemented in [12-13], adapti v e windo w [14], con v olution neural netw ork [15] and multiple windo ws [16]. In common, W inner - T ak es-All (WT A) strate gy is applied for local based optimization. It is lo w computational comple xity and f ast e x ecution time [17-19]. Local method such i mplemented in [20] that used plane fitting technique to increase the accurac y at the final stage. This method also kno wn as RANSA C that ef ficiently w orks on the lo w te xtured areas. Ho we v er , the error still occurred on the object edges. Their method requires se v eral iterations for plane fitting process. If wrong iterations, then it will af fect the results. Commonly , local methods sho w f ast running time, b ut lo w accurac y on the edges due to improper sele ction of windo ws sizes. Hence, to get an accurate result for the local approach is a challenge to the researchers. Another approach in stereo matching algorithm to produce the disparity map is global opti mization method. Fundamentally , this method uses ener gy-based function which is kno wn as Mark o v Random Field (MRF). The method in global optimization such as Belief Propag ation (BP) [21] and Graph Cut (GC) [22] produce accurate result s. Each pix el of interest calculation requires all pix el’ s ener gy in dispar - ity map. It calculates neighboring or nearby pix els using maximum flo w and the selection is made based on the minimum cut-of f ener gy on the disparity map. The algorithms implemented using global optimization approach normally in v olv e high computational requirement due to all pix el’ s ener gy calculation and absorp- tion. Global methods in v olv e iterations which increase the e x ecution time each disparity map reconstruction. This article aims to produce accurate results and competiti v e with some established methods. The first function or stage will be implemented using impro v ed Sum of Absolute Dif ferences (SAD) [23] with gradient match- ing. Then, the second stage utilizes the edge preserving filter which is kno wn as Bilateral Filter (BF) [24]. This filter is capable t o remo v e noise and preserv ed object edges. The third stage is optimization based on WT A strate gy . Last stage, the BF is applied once ag ain to remo v e unw anted or remaining in v alid pix els. The BF is also capable to increase the accurac y at object boundaries. 2. RESEARCH METHOD The diagram of the proposed w ork is dispalyed by Figure 1. The stereo matching algorithm starts with STEP 1 to get the preliminary disparity map. The impro v ed SAD has been proposed which the weighted technique is used on the block matching process. The combination of impro v ed SAD with gradient match- ing in this article should be able to increase the ef fecti v eness of corresponding process and accurac y . Then at STEP 2, the BP is utilized to reduce the noise and preserv ed the object edges. The BP is capable to ef ficiently remo v e noise on the lo w te xture re gions and sharping the object boundaries. The optimization uses WT A strate gy which this method normalizes the floating point s numbers and selects minimum disparity v alues on the disparity map. Final stage at STEP 4 is also using the BP b ut with the disparity v alues. This filter is a type of nonlinear filter and capable to impro v e final disparity map. Figure 1. A flo wchart of the proposed algorithm. Int J Elec & Comp Eng, V ol. 10, No. 3, June 2020 : 2375 2382 Evaluation Warning : The document was created with Spire.PDF for Python.
Int J Elec & Comp Eng ISSN: 2088-8708 r 2377 2.1. Matching cost computation The first stage of the proposed frame w ork is using the weighted SAD. The preliminary disparity map is produced at this stage. Hence, rob ust function must be used to increase the ef fecti v eness on the dispar - ity map. The problem on matching process at this stage on the lo w te xture re gions must be at minimum. The weight is proposed at SAD to impro v e the v alues on the lo w te xture re gions. Thus, the consistenc y of the weight at t he lo w te xture re gion is capable to mak e the matching process accurate and reduces the mismatch or in v alid pix els. The RGB v alues are used with the weight of sum of intensity dif ferences on right image I r and left image I l which is gi v en by (1): SAD ( x; y ; d ) = 1 W X ( x;y ) 2 w j I i l ( x; y ) i I i r ( x d; y ) j (1) where ( x; y ) are the coordinates pix el of interest with d represents the disparity v alue, W is the proposed weight, RGB channels numbers are i and w represents k ernel of SAD algorithm. The second part is gradient matching components. It contains the magnitude dif ferences from each image. There will be tw o directions that need to be calculated on this gradient dif ferences. V ertical direction G y and horizontal direction of G x are the directions with the equations are gi v en by (3) and (2): G y = 2 4 1 0 1 3 5 I m (2) G x = 1 0 1 I m (3) where I m is input image and represents con v olution operation on the gradient matching. The G x and G y are the gradient magnitude for m which is gi v en by (4): m = q G 2 x + G 2 y (4) (5) is the gradient matching k ernel G ( x; y ; d ) . G ( x; y ; d ) = j m l ( x; y ) m r ( x d; y ) j (5) The matching cost function at this stage is gi v en by (6) where the input v ol ume of S AD ( x; y , d ) and G ( x; y , d ) are combined together . M C ( x; y ; d ) = S AD ( x; y ; d ) + G ( x; y ; d ) (6) 2.2. Cost aggr egation This second stage more lik ely to filter the preliminary disparity map from stage one. Normally the preliminary disparity map contains high noise and it must be remo v ed. Some of in v alid and uncertainties pix els are constructed during the matching process. Hence, at this stage the filter must be rob ust and is capable to remo v e high noise of in v alid pix els and preserv ed the object boundaries. The BP is used due to strong preserving object edges a nd at the same time ef ficient to remo v e high noise especially on the plain color and lo w te xture re gions. (7) is the BF function used in this article. W B F ( p; q ) = X q 2 w B exp j p q j 2 2 s exp j I p I q j 2 2 c (7) where p is the location pix el of interest at ( x , y ), w B and q are windo w size of BF and neighboring pix els respecti v ely . The s denotes a f actor of spatial adjustment and c equals to similarity f actor for the color detection. The p q is spatial Euclidean interv al and j I p I q j denotes the Euclidean distance in color space. Hence, (8) is the cost aggre g ation function of BF with the matching cost computation input. C ( p; d ) = W B F ( p; q ) M C ( p; d ) (8) De velopment of ster eo matc hing algorithm based on... (Rostam Af fendi Hamzah) Evaluation Warning : The document was created with Spire.PDF for Python.
2378 r ISSN: 2088-8708 2.3. Disparity optimization This stage optimizes the disparity v alues on disparity map. The normalization is based on the minimum disparity v alues with the floating-point number which the WT A is selected in this article. The WT A is normally being used in the local based methods due to f ast im plementation. The WT A function is gi v en by (9). d x;y = ar g min d 2 D C ( p; d ) (9) where D represents a set of v alid disparity v alues for an image and C ( p; d ) denotes the second stage of aggre g ation step. Fundamentally , after this stage the disparity map still contains noise or in v alid pix els. Thus, this map needs to be impro v ed and the last stage is will remo v e remaining noise. 2.4. Disparity r efinement The last st age of the algorithm frame w ork is kno wn as refinement or post processing stage. It has se v eral continuous processes which starts with handling the occlusion re gions, filling the in v alid pix els and filtering final disparity map. The left-right consistenc y checking process is conducted to identify occlusion areas and some in v alid pix els. Then, these in v alid pix els are restored with v alid pix el v alues through the filling process. Some of artif acts and unw anted pix els will be remo v ed using the BF and at the same time preserv ed the object boundaries. The BF smoothes the final disparity map as indicates by (7). 3. RESUL T AND AN AL YSIS This section e xplains about the disparity map results that will be represented by color -scale intensity . The dif ferent color tones sho w that the respected objects are mapped based on the dispari ty v alues and the distance sensor (i.e., stereo camera). Most probably the lighter intensity v olume indicates that the object is closer to the sensor . The e xperimental analysis has been e x ecuted on a personal computer with W indo ws 10, 3.2GHz and 8G RAM. The input images are from the Middleb ury stereo e v aluation dataset [24] which contains 15 standard images and must be submitted online. These images are v ery comple x, and each image consists of dif ferent characteristics and properties such as light settings objects depth, incoherence re gions, dif ferent resolutions and lo w te xture areas. The v alues of f w ; s ; c ; w B g are f 9 x 9 ; 17 ; 0 : 4 ; 11 x 11 g . Figure 2 sho ws a sample Jadeplant image (i.e., left and right) from the Middleb ury training dataset with dif ferent brightness and hi gh contrast. Generally , due to the brightness dif ference, these input images are v ery challenging to be matched. It contains dif ferent pix el v alues at the same corresponding point. Ho we v er , the proposed algorithm is correctly disco v ered the disparity locations. The le v el of disparity contour are precisely assigned and object distance are well-recognized. Figure 3 sho ws the final disparity map results of 15 training images from the Middleb ury dataset. The accurac y attrib utes for error e v aluation are nonocc (non-occluded) and all error . The nonocc error is the error e v aluation based on t he non-occluded re gions on dis p a rity map while all error represents the all pix els’ e v aluation on an image of disparity map. W ithin these 15 images, Pipes and Jadeplant images are the most dif ficult images to be matched. These images comprise se v eral piping lines and lea v es with dif ferent sizes respecti v ely . Y et, the propose algorithm can reconstruct almost accurate disparity map with clear discontinuities re gions. Fundamentally , real images from the Middleb ury are dif ficult and v ery challenging to get an accurate corresponding point. It w as de v eloped to test the rob ustness of an algorithm where same corresponding point maybe contains dif ferent pix el v alues. Additionally , each image contains dif ference characteristics such as plain color objects, shado w , discontinuity re gions and occluded areas. W ith referring to Figure 3, the disparity maps of lo w te xture surf aces such as Motorc ycle, Motorc y- cleP , Playtable and PlaytableP are well recreated with dif ferent depth and disparity contour . Other re gions dif ficult to be matched are plain colour objects and shado w such as images of ArtL, Rec ycle, Piano and PianoL. These re gions consist of similar pix el v alues and possibility to get wrong matching are v ery high. The dispa rity maps from the proposed w ork display almost accurate matching for these images. It sho ws that the proposed w ork is able to get correct matching pix els o n these re gions and rob ust ag ainst the plain colour areas. The quantitati v e measurement from the Middleb ury online results are gi v en in T ables 1 and 2. These results are produced by the Middleb ury online benchmarking e v aluation system with tw o error attrib utes as e xplained abo v e. Some established methods are also included in these T ables to sho w the competiti v eness of the proposed w ork. Ov erall, an a v erage error measurement is assessed to rank the best results. F or T able 1, the proposed method is rank ed at top of the table with 6.11%, and T able 2 with 9.15%. It sho ws that the proposed w ork is competiti v e with other recently published methods and can be used as a complete algorithm. The proposed Int J Elec & Comp Eng, V ol. 10, No. 3, June 2020 : 2375 2382 Evaluation Warning : The document was created with Spire.PDF for Python.
Int J Elec & Comp Eng ISSN: 2088-8708 r 2379 w ork is rank at top compared to [15-17,19,25,26] for nonocc error . The weight a v erage error is 6.11% where Jadepl, Playrm and V intge images are the lo west error produced. F or the al l error attrib ute in T able 2, the proposed w ork is produced at 9.15% which is the lo west a v erage error . It sho ws that the proposed w ork in this article is competiti v e with some established methods. Figure 2. Dif ferent brightness and contrast of the input Jadeplant stereo images. Accurate disparity map result is produced by the proposed w ork compared to the image without the proposed w ork. The plant structures are clearly displayed and smooth disparity map can be notified Figure 3. These final disparity images are from the Middleb ury dataset which the results tab ulated in T able 1 and T able 2 T able 1. The nonocc error results using the Middleb ury dataset. The comparison results with other published methods Algorithms Adiron ArtL Jadepl Motor MotorE Piano PianoL Pipes Playrm Playt PlayP Rec yc Shelvs T eddy V intge W eight A v e Proposed Algorithm 3.66 4.23 19.54 3.11 3.87 5.01 11.02 6.32 5.11 24.85 5.10 3.33 7.52 2.21 7.90 6.11 SNCC [19] 2.89 4.05 18.10 2.68 2.52 3.52 7.08 6.14 5.64 45.40 3.13 2.90 7.59 1.58 13.50 6.97 ELAS [26] 3.09 4.72 29.70 3.28 3.29 4.30 8.31 5.61 6.00 21.80 2.84 3.09 9.00 2.36 10.90 7.22 MPSV [15] 3.83 6.00 19.70 5.85 5.53 5.68 34.30 9.59 5.86 15.30 4.20 4.59 13.00 3.70 14.30 8.81 ADSM [16] 13.30 6.10 15.00 3.67 5.67 7.08 20.60 6.57 13.20 23.10 3.55 5.76 17.20 3.05 10.10 8.95 DoGGuided [17] 15.20 9.57 27.10 5.64 8.31 8.09 32.40 9.67 14.00 24.50 5.32 5.56 16.20 4.15 15.00 12.00 BSM [25] 7.27 11.40 30.50 6.67 6.52 10.80 32.10 10.50 12.50 24.40 12.80 7.42 16.40 4.88 32.80 13.40 De velopment of ster eo matc hing algorithm based on... (Rostam Af fendi Hamzah) Evaluation Warning : The document was created with Spire.PDF for Python.
2380 r ISSN: 2088-8708 T able 2. The al l error results using the Middleb ury dataset. These comparisons sho w the competiti v eness of the proposed method Algorithms Adiron ArtL Jadepl Motor MotorE Piano PianoL Pipes Playrm Playt PlayP Rec yc Shelvs T eddy V intge W eight A v e Proposed Algorithm 4.74 7.45 27.21 5.57 5.54 6.01 11.64 11.77 7.31 27.05 8.54 3.86 9.21 3.33 8.87 9.15 SNCC [19] 3.63 6.78 39.80 5.12 5.11 4.65 8.23 11.80 8.05 45.60 4.36 3.29 8.10 2.55 14.80 10.40 ELAS [26] 4.08 7.18 52.80 5.39 5.45 4.96 9.00 10.70 7.94 23.20 3.83 3.78 9.46 3.34 11.60 10.60 ADSM [16] 14.30 10.60 34.10 6.00 8.00 7.37 20.40 12.10 16.90 25.50 5.84 5.83 17.20 4.11 11.10 12.30 MPSV [15] 5.87 9.43 40.20 9.11 8.80 7.03 34.20 15.80 8.58 16.90 5.89 6.78 13.70 4.82 16.80 12.70 DoGGuided [17] 20.10 28.00 56.50 13.80 16.80 13.40 37.30 23.80 30.30 30.80 13.00 9.13 19.00 13.40 23.60 22.30 BSM [25] 12.70 2 8.70 58.70 14.80 14.70 16.00 35.80 24.50 29.40 31.00 20.20 12.10 19.20 14.30 39.30 23.50 T o v erify the potentiality of the proposed algorithm, the images from the KITTI [27] are also tested. These images are more dif ficult and challenging to be matched. It contains comple x edges and structures such as shado w , plain color surf aces, high dif ferent contrast and brightness areas with lar ge unte xtured re gions. The e xperimental results are sho wn in Figure 4. The disparity map results sho w accurate disparity v alues estimation in grayscale. As for reference, the signage, a c yclist, trees and cars, are well-reconstructed with correct disparity le v el. It sho ws the proposed w ork in this article capable to w ork with dif ficult stereo images from real en vironment. Figure 4. The disparity map results from the KITTI training dataset. This article utilizes images from the number of #000004 10-#000007 10 4. CONCLUSION In this w ork, the combination of SAD algorithm based RGB color and gradient matching are producing accurate results. The second stage where edge preserving filter is utilized. The BF at the aggre g ation stage is capable to filter high noise and conserv e the object bound a ries of the preliminary disparity map. The WT A strate gy w as implemented at the optimization stage to normalize the floating points numbers to the disparity v alues. The second edge preserving filter w as used at the last stage of the proposed w ork using the same BF . This nonlinear filter remo v ed remaining noise and increase the ef ficienc y of final disparity map. Ov erall, these edge preserving filters used in the proposed frame w ork were able to rem o v e noise especially on the lo w te xture re gions and able to preserv e the object edges as sho wn by Figure 2. The quantitati v e measurement from the standard benchmarking Middleb ury system also demonstrated lo w a v erage errors were produced by the proposed frame w ork at 6.11% and 9.15% of non-occluded and all pix el errors respecti v ely . The training images are sho wn by Figure 3. From real images of the KITTI, the proposed w ork w as also demonstrated accurate results. Int J Elec & Comp Eng, V ol. 10, No. 3, June 2020 : 2375 2382 Evaluation Warning : The document was created with Spire.PDF for Python.
Int J Elec & Comp Eng ISSN: 2088-8708 r 2381 A CKNO WLEDGEMENT This project w as sponsored by a grant from the Uni v ersiti T eknikal Malaysia Melaka with the Nu m ber: JURN AL/2018/FTK/Q00008. REFERENCES [1] S. F . Gani, et al., ”De v elopment of portable automatic number plate recognition (ANPR) system on Rasp- berry Pi, International Journal of Electrical and Computer Engineering , v ol. 9, pp. 1805–1813, 2019. [2] R. A. Hamzah, et al., ”Stereo Matching Algorithm for 3D Surf ace Reconstruction Based on T riangulation Principle, in International Conference on Information T echnology , Information Systems and Electrical Engineering (ICITISEE), , 2016, pp. 119–124, 2016. [3] S.F . Gani, et al., ”De v elopment of a portable community video surv eillance system, International Journal of Electrical & Computer Engineering , v ol. 9, pp. 1814–1821, 2019. [4] D Scharstein, et al., ”A T axonomy and Ev aluation of Dense T w o-frame Stereo Correspondence Algo- rithms, in Stereo and Multi-Baseline V ision, 2001.(SMBV 2001). Proceedings. IEEE W orkshop on , 2001, pp. 131–140. [5] R. Christian, et al., ”Dens e W ide-Baseline Scene Flo w From T w o Handheld V ideo Camera s, IEEE T rans- action on Circuit and Systems for V ideo T echnology , v ol. 26, pp. 1–18, 2016. [6] Q. Y ang, ”A Non-local cost aggre g ation Method for Stereo Matching, in IEEE Conference on Computer Vision and Pattern Recognition (CVPR) , 2012, pp. 1402–1409. [7] H. Asmaa, et al., ”F ast Cost-v olume Filtering for V isual Correspondence and Be yond, IEEE T ransactions on P attern Analysis and Machine Intelligence , v ol. 35, pp. 504–511, 2015. [8] H. Ibrahim, et al., ”Stereo matching algorithm based on illumination control to impro v e the accurac y , Image Analysis & Stereology , v ol. 35, pp. 39–52, 2016. [9] L. Qian, et al., ”Stereo Matching Algorithm Based on Ground Control Points Using Graph Cut, in Image and Signal Processing (CISP), 2014 7th International Congress on , 2014, pp. 503–508. [10] W . Sih-Sian, et al., ”Ef ficient Hardw are Architecture for Lar ge Disparity Range Stereo Matching Based on Belief Propag ation, in Signal Processing Systems (SiPS), 2016 IEEE International W orkshop on , 2016, pp. 236–241. [11] H. Hirschm ¨ uller , et al., ”Real-time Correlation-based Stereo V ision with Reduced Border Errors, Interna- tional Journal of Computer V ision , v ol. 47, pp. 1-3, 2002. [12] K. Jedrzej, et al., ”Real-time Stereo Matching on CUD A Us ing an Iterati v e Refinement Method for Adap- ti v e Support-weight Correspondences, IEEE T ransactions on Circuits and Systems for V ideo T echnology , v ol. 23, pp. 94–104, 2013. [13] Q. Y ang, et al., ”F ast Stereo Matching Using Adapti v e Guided Filtering, Image and V ision Computing , v ol. 32, pp. 202–211, 2014. [14] J. Zbontar and Y . LeCun, ”Computing The Stereo Matching Cost with a Con v olution Neural Netw ork, in IEEE Conference on Computer V ision and P attern Recognition , 2015, pp. 1592–1599. [15] B. Jean-Charles et al., ”Morphological Processing of Stereoscopic Image Superimpositions for Disparity Map Estimation, Hal-01330139 , pp. 1–17, 2016. [16] M. Bing et al., ”Accurate Dense Stereo Matching Based on Image Se gmentation Using an Adapti v e Multi-Cost Approach, Symmetry , v ol. 8, p. 159,2016. [17] K. Masamichi, et al., ”High Accurac y Local Stereo Matching Using DoG Scal e Map, ”in Fifteenth IAPR International Conference on Machine V ision Applications ,2017, pp. 258–261. [18] W . Hu, et al., ”V irtual Support W indo ws for Adapti v e-weight Stereo Matching, in V isual Communica- tions and Image Processing (VCIP), 2011 IEEE , 2011, pp. 1–4. [19] E. Nils and E. Julian, ”Anisotropic Median Filtering for Stereo Disparity Map Refinement., in VISAPP (2) , 2013, pp. 189–198. [20] K.A.A. Aziz, et al., ”A pix el to pix el correspondence and re gion of interest in stereo vision application”, in 2012 IEEE Symposium on Computers & Informatics (ISCI) , pp. 193–197, 2012. [21] M.G.Y . W ei, et al., ”Stereo matching based on absolute dif ferences for multiple objects detection, T elk omnika , v ol. 17, pp. 261-267, 2019. [22] A. H. Hasan, et al., ”Disparity Mapping for Na vig ation of Stereo V ision Autonomous Guided V ehicle, in Soft Computing and P attern Recognition, 2009. SOCP AR’09. International Conference of , 2009, pp. De velopment of ster eo matc hing algorithm based on... (Rostam Af fendi Hamzah) Evaluation Warning : The document was created with Spire.PDF for Python.
2382 r ISSN: 2088-8708 575–579. [23] R. A. Hamzah et al., ”V isualization of image distortion on camera calibration for stereo vision applica- tion, in Control System, Computing and Engineering (ICCSCE), 2012 IEEE Inter national Conference on , 2012, pp. 28–33. [24] S. Daniel and S. Richard, Middleb ury Stereo Ev aluation - V ersion 3 (Accessed date : No v ember 2019, http://vision.middleb ury .edu/stereo/e v al/references., 2019. [25] K. Zhang, et al., ”Binary Stereo Matching, in P attern Recognition (ICPR), 2012 2 1s t International Con- ference on , 2012, pp. 356–359. [26] A. Geiger et al., ”Ef ficient Lar ge-scale Stereo Matching, in Asian Conference on Computer V ision , 2010, pp. 25–38. [27] M. Menze and G. Andreas, ”Object Sflo w for Autonomous V ehicles, in IEEE Conference on Computer Vision and Pattern Recognition (CVPR) , 2015, pp. 3061–3070. BIOGRAPHIES OF A UTHORS Rostam Affendi Hamzah w as graduated from Uni v ersiti T eknologi Malaysia where he recei v ed his B.Eng majoring in Electronic Engineering. Then he recei v ed his M. Sc. majoring in Electronic System Design engineering from the Uni v ersiti Sains Malaysia in 2010. In 2017, he recei v ed PhD majoring in Electronic Imaging from Uni v ersiti Sains Malaysia. Currently he is a lecturer in the Uni v ersiti T eknikal Malaysia Melaka teaching digital electronics, digital image processing and embedded system. Melvin Gan Y eou W ei w as born in 1992, Melvin Gan Y eou W ei graduated from Uni v ersiti T eknikal Malaysia Melaka where he recei v ed his B.Eng majoring in Electrical in 2017. Curre ntly , he is pursuing a Master De gree in the Uni v ersiti T eknikal Malaysia Melaka. Nik Syahrim Nik Anwar w as born in 1981, Nik Syahrim graduated from Uni v ersity of Applied Science Heilbronn, German y where he recei v ed his Diplom in Mechatronik und Mikrosystemtechnik majoring in Mechatronics in 2006. In 2010 he recei v ed his M. Sc. majoring in Mechatronics from the Uni v ersity of Applied Science Aachen, German y . In 2018, he recei v ed PhD majoring in Electrical from the Uni v ersiti Sains Malaysia. Currently he is a lecturer in Uni v ersiti T eknikal Malaysia Melaka teaching Electrical and Mechatronics subjects. Int J Elec & Comp Eng, V ol. 10, No. 3, June 2020 : 2375 2382 Evaluation Warning : The document was created with Spire.PDF for Python.