Identifikasi Homogenitas Kontur Permukaan Amplas Menggunakan Citra Spekel dengan Metode Gray Level Co-Occurrence Matrix (GLCM) dan Fast Fourier Transform (FFT)

Mahera, Rizka Intan (2026) Identifikasi Homogenitas Kontur Permukaan Amplas Menggunakan Citra Spekel dengan Metode Gray Level Co-Occurrence Matrix (GLCM) dan Fast Fourier Transform (FFT). Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Karakterisasi tekstur permukaan material merupakan salah satu aspek penting dalam berbagai aplikasi industri, termasuk pada material abrasif seperti amplas. Metode pengukuran konvensional umumnya menggunakan kontak langsung dengan permukaan sehingga berpotensi menyebabkan kerusakan pada sampel. Oleh karena itu, pada penelitian ini digunakan metode optik non-kontak berbasis citra spekel laser untuk mengidentifikasi karakteristik tekstur permukaan amplas. Penelitian dilakukan menggunakan sampel amplas dengan variasi grit P800, P1000, P1500, P2000, P3000, P4000, dan P5000. Citra spekel diperoleh menggunakan sistem pencitraan berbasis laser He-Ne dan webcam tanpa lensa. Karakteristik tekstur dianalisis menggunakan metode Gray Level Co-occurrence Matrix (GLCM) berdasarkan parameter kontras, homogenitas, korelasi, dan entropi. Distribusi intensitas citra spekel divisualisasikan menggunakan peta kontur, sedangkan karakteristik tekstur pada domain frekuensi dianalisis menggunakan metode Fast Fourier Transform (FFT) berdasarkan parameter orientasi tekstur, Texture Aspect Ratio (Str), dan Axial Ratio (AR). Hasil penelitian menunjukkan bahwa peningkatan nomor grit secara umum menyebabkan nilai kontras dan entropi menurun, sedangkan nilai homogenitas meningkat. Nilai korelasi pada seluruh variasi grit tetap berada pada rentang yang tinggi di atas 0,95. Visualisasi peta kontur menunjukkan bahwa distribusi intensitas citra spekel tidak tersebar secara merata dan membentuk daerah dengan nilai maksimum maupun minimum pada area pengamatan. Hasil analisis FFT menunjukkan bahwa seluruh variasi amplas memiliki orientasi tekstur yang relatif seragam dengan nilai Str berkisar antara 0,1576–0,1629 dan nilai AR berkisar antara 0,4539–0,4774 yang mengindikasikan karakteristik tekstur anisotropik. Berdasarkan hasil tersebut, citra spekel laser yang dikombinasikan dengan metode GLCM dan FFT mampu digunakan untuk mengidentifikasi karakteristik tekstur permukaan amplas secara non-kontak dan non-destruktif pada berbagai variasi grit.
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Surface texture characterization is an important aspect in various industrial applications, including abrasive materials such as sandpaper. Conventional measurement methods generally require direct contact with the surface, which may potentially damage the sample. Therefore, this study employs a non-contact optical method based on laser speckle imaging to identify the surface texture characteristics of sandpaper. The study was conducted using sandpaper samples with grit variations of P800, P1000, P1500, P2000, P3000, P4000, and P5000. Speckle images were acquired using a He–Ne laser imaging system and a lensless webcam. Surface texture characteristics were analyzed using the Gray Level Co-occurrence Matrix (GLCM) method based on contrast, homogeneity, correlation, and entropy parameters. The intensity distribution of the speckle images was visualized using contour mapping, while texture characteristics in the frequency domain were analyzed using the Fast Fourier Transform (FFT) method based on texture orientation, Texture Aspect Ratio (Str), and Axial Ratio (AR). The results show that increasing the grit number generally leads to a decrease in contrast and entropy values, while the homogeneity value tends to increase. Correlation values remained high for all grit variations, exceeding 0.95. Contour map visualization indicates that the speckle intensity distribution is not uniformly distributed and forms regions with maximum and minimum values within the observation area. FFT analysis shows that all sandpaper samples exhibit relatively similar texture orientations, with Str values ranging from 0.1576 to 0.1629 and AR values ranging from 0.4539 to 0.4774, indicating anisotropic texture characteristics. Based on these results, laser speckle imaging combined with GLCM and FFT methods can be used as a non-contact and non-destructive approach for identifying the surface texture characteristics of sandpaper with different grit variations.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Amplas, Citra Spekel Laser, GLCM, FFT, Tekstur Permukaan. Laser Speckle Imaging, GLCM, FFT, Sandpaper, Surface Texture
Subjects:	Q Science Q Science > Q Science (General) Q Science > QC Physics Q Science > QC Physics > QC20.7.F67 Fourier transformations Q Science > QC Physics > QC411 Interferometry.
Divisions:	Faculty of Science and Data Analytics (SCIENTICS) > Physics > 45201-(S1) Undergraduate Thesis
Depositing User:	Rizka Intan Mahera
Date Deposited:	30 Jul 2026 07:40
Last Modified:	30 Jul 2026 07:40
URI:	http://repository.its.ac.id/id/eprint/139682

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