Perhitungan area basah yang dilakukan dengan bantuan kertas milimeter blok mempunyai kelemahan pada penyalinan tepian yang kurang tepat dan waktu perhitungan yang cukup lama. Masalah lain adalah konsistensi dan ketelitian yang dihasilkan tergantung pada faktor subyektif manusia dan kelelahan seseorang. Agar proses lebih tepat dan lebih konsisten, proses perhitungan menggunakan pengolahan citra sangat diperlukan. Prapemrosesan citra antara lain cropping, grayscalling, lowpass filter averaging, konversi ke citra biner berdasarkan otsu thresholding, dan komplemenkan citra agar piksel objek bernilai 1. Segmentasi dengan operasi morfologi, antara lain operasi opening untuk menghilangkan objek-objek kecil di sekeliling objek, operasi Filling Holes untuk mengisi lubang pada objek, operasi opening lagi untuk menghilangkan objek selain area basah. Proses perhitungan luas area basah menggunakan chain code. Berdasarkan hasil pengujian terhadap 81 citra, penggunaan operasi morfologi mampu menghasilkan segmentasi area basah yang mendekati area basah aslinya. Nilai skala berpengaruh terhadap akurasi dan skala terbaik diperoleh dari penggunaan mistar. Penggunaan chain code mampu menghitung luas area basah pada kertas saring dengan rata-rata akurasi 95,73%, nilai tersebut lebih tinggi daripada penggunaan luas dengan menjumlahkan nilai piksel meskipun tidak signifikan. Rata-rata perhitungan area basah menggunakan sistem sekitar 0.8 detik atau 379 kali lebih cepat daripada menggunakan milimeter blok.

Calculation of wet areas carried out with the help of milimeter block paper has the disadvantage of copying the edges that are less precise and the calculation time is quite long. Another problem is the consistency and accuracy that is generated depends on the subjective factors of the person and one's fatigue. In order for the process to be more consistent and precise, the calculation process using image processing is very necessary. Image preprocessing includes cropping, grayscalling, lowpass filter averaging, convertion to binary image based on otsu thresholding, and complementing images to pixel objects of value 1. Segmentation with morphological operations, including opening operations to remove small objects around objects, Holes Filling operations to fill holes in objects, opening operations again to remove objects other than wet areas. The process of calculating wet areas uses chain code. Based on the results of testing of 81 images, the use of morphological operations is able to produce segmentation of wet areas that approach the original wet area. The scale value affects the accuracy and the best scale is obtained from the use of the ruler. The use of chain code is able to calculate the wet area on filter paper with an average accuracy of 95.73%, the value is higher than extensive use by summing the pixel value even though it is not significant. The average calculation of wet areas uses a system of about 0.8 seconds or 379 times faster than using milimeter block.

Kata Kunci : Luas Area Basah, Operasi Morfologi, Kode Rantai