July 2019
Intermediate to advanced
365 pages
8h 13m
Chinese
Content preview from Python机器学习手册：从数据预处理到深度学习
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8.15
将色彩直方图编码成特征
｜
157
#
显示图像
plt.imshow(observation), plt.axis("off")
plt.show()
讨论
本节代码的输出结果是样本的三个特征值，分别来自图像的各颜色通道。这些特征可以
和其他特征一样用于机器学习算法，根据颜色对图像进行分类。
8.15
将色彩直方图编码成特征
问题描述
创建一组特征来表示图像中的颜色。
解决方案
计算每一个颜色通道的直方图 ：
#
加载库
import cv2
import numpy as np
from matplotlib import pyplot as plt
#
加载图像
image_bgr = cv2.imread("images/plane_256x256.jpg", cv2.IMREAD_COLOR)
#
将图像转换成
RGB
格式
image_rgb = cv2.cvtColor(image_bgr, cv2.COLOR_BGR2RGB)
#
创建一个特征列表
features = []
158
｜
第
8
章
图像处理
#
为每一个颜色通道计算直方图
colors = ("r","g","b")
#
为每一个通道计算直方图并把它加入特征列表中
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