PR Notes

Pattern recognition — the act of taking in raw data and taking an action based on the “category” of the pattern .

Segmentation operation in which the images of different fish are somehow isolated from one another and from the background. 比如把某隻魚從其他的魚中獨立出來並且去除背景,此動作叫做Segmentation。

Feature 的好壞 : 當一個 feature f1 和 feature f2 有相關性 ( 比如是正相關 ) .
則同時選擇 f1 和 f2 當 feature並沒有什麼意義,對 classification 的效果也不會提升。

用太複雜的 model 來做 decision 並不一定是好的,很難有 generalization 的效果。
也就是會造成Overfitting。簡單就是好。

Given that there truly are differences between the population of sea bass and that
of salmon, we view them as having different models — different descriptions, which
are typically mathematical in form. 盧魚和鮭魚顯然有著不同的特質,比如外觀,
長度,顏色等。諸如此類的特性,我們稱之為 Model。我們常常會用數學式來描述
Model,比如說長度 > 50 以上就是盧魚,<=50就是鮭魚。此為簡單的Model,
因此為了要區分盧魚和鮭魚所做出的decision boundary就很簡單。

Syntactic pattern recognition, where rules or grammars describe our decision. For ex-
ample we might wish to classify an English sentence as grammatical or not, and here
statistical descriptions (word frequencies, word correlations, etc.) are inapapropriate.
Syntactic的方式比較類似定 rule 來描述我們的 decision。

Pattern 表示法可以採用 vector 表示。

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