Table 1.

Different classification results of Scene8 Dataset.

Criterion	Class Number	The Combination of Tags
1	7	opencountry ←{opencountry, forest} *
2	7	insidecity←{insidecity, street}
3	6	opencountry ←{opencountry, forest}, insidecity←{insidecity, street}
4	4	natural ←{coast, forest, mountain, opencountry}, insidecity←{insidecity, street}
5	2	natural ←{coast, forest, mountain, opencountry}, manmade←{insidecity, street, highway, tallbuilding}

* ‘opencountry ←{opencountry, forest}’ means we combine ‘opencountry’ and ‘forest’ into one category ‘opencountry’.