Global Journal of Computer Science and Technology, G: Interdisciplinary, Volume 23 Issue 1

or scene relative to the camera, and vice versa. To realize this, Gaussian blur was carried out using a kernel size (5,15). • Contrast and Brightness The Contrast and Brightness function improves the appearance of an image. Brightness improves the overall clarity of the image and contrast adjusts the difference between the darkest and lightest colors. Contrast parameters used are {0.5;2;2.5} and brightness parameters are {1;4;5}. For each original image, three new images are generated with respectively the following parameters contracts, brightness {c; b}: {0.5; 1}, {2; 4}, {2.5; 5}. • Zoom Zooming an image means enlarging it in a sense that the details in the picture became more visible and clear. Each image is zoomed three times and from the center using zoom parameters {3;5;7}. • Image flipping To flip or mirror an image means to turn it horizontally (horizontal flip) or vertically (vertical flip). Flip function generates an image so that the left side becomes the right side or the top becomes the bottom. The images are vertically and horizontally flipped using flip parameter 0 and 1 respectively. • Affine transformation An affine transformation is, in general a combination of translations, rotations, shears and dilations [12]. It s used to simulate images captured from different camera projections nd positions. Affine transformation is performed using an input matrix (In) of size 2x3 and an output matrix (Out) of the same size. The input matrix corresponds to three points in the input image and the second matrix is their corresponding locations in the output image. In the training dataset, twenty additional images are randomly generated for each image. But after that, the generated images on which there is no part of mango leaf are removed. Fig.3 shows an example of a diseased mango leaf (anthracnose) on which all these data augmentation techniques are applied. Fig. 1: Ranking of the most common and treated mango diseases [19] Anthracnose Gall Midge Powdery Mildew Sooty Mould Healthy Fig. 2: Dataset image composition 12 5 5 4 3 3 0 2 4 6 8 10 12 14 Number of times Mango Diseases A Combination of Data Augmentation Techniques for Mango Leaf Diseases Classification © 2023 Global Journals Global Journal of Computer Science and Technology Volume XXIII Issue I Version I 3 ( )G Year 2023