{"id":14495,"date":"2014-07-09T07:05:06","date_gmt":"2014-07-09T12:05:06","guid":{"rendered":"http:\/\/gisgeography.com\/?p=14495"},"modified":"2025-04-01T19:37:26","modified_gmt":"2025-04-02T00:37:26","slug":"obia-object-based-image-analysis-geobia","status":"publish","type":"post","link":"https:\/\/gisgeography.com\/obia-object-based-image-analysis-geobia\/","title":{"rendered":"OBIA – Object-Based Image Analysis (GEOBIA)"},"content":{"rendered":"
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\"OBIA<\/figure>\n<\/div>\n\n\n
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Think objects, not pixels<\/h3>\n\n\n\n

How amazing would it be if you could digitize all your features in an image with just a click of a button?<\/p>\n\n\n\n

On top of that, you can classify each feature with another click of a button.<\/p>\n\n\n\n

Sounds like magic? But these two processes are segmentation and classification performed in Object-based Image Analysis (OBIA)<\/strong>. <\/p>\n\n\n\n

Let’s examine what it is and how you can use it to get your work done more efficiently and accurately.<\/p>\n<\/div><\/div>\n\n\n\n

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Segmentation is key to classification<\/h3>\n\n\n\n

Human visual perception almost always outperforms computer vision algorithms.<\/p>\n\n\n\n

For example, your eyes know a river when they see one. But a computer can’t recognize rivers from lakes.<\/p>\n\n\n\n

…Or can it?<\/p>\n\n\n\n

Traditional pixel-based image classification<\/a> assigns a land cover class per pixel. All pixels are the same size, same shape, and don’t have any concept of their neighbors.<\/p>\n\n\n\n

However, OBIA segments an image grouping small pixels together into vector objects. Instead of a per-pixel basis, segmentation automatically\u200b digitizes the image for you. <\/p>\n\n\n

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\"OBIA
Object-Based Image Analysis (OBIA) segmentation is a process that groups similar pixels into objects<\/figcaption><\/figure>\n<\/div>\n\n\n

What segmentation does is replicate what your eyes are doing. <\/p>\n\n\n\n

But with these\u200b segmented objects, you use their spectral, geometrical, and spatial properties to classify them into land cover.<\/p>\n\n\n

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\"OBIA
OBIA classification uses shape, size, and spectral properties of objects to classify each object<\/figcaption><\/figure>\n<\/div>\n\n\n

Otherwise, when you use traditional image classification techniques, you often get a salt-and-pepper look in the classification result.<\/p>\n\n\n\n

To recap, the two basic principles of OBIA are:<\/p>\n\n\n\n