首先是免责声明，我对Python不是很熟练，你们有我的钦佩。
我的问题： 我需要从模板（128px到128px）生成10k +图像，具有各种色调和亮度。
我加载图像并将它们转换为数组
image = Image.open(dir + "/" + file).convert('RGBA')
arr=np.array(np.asarray(image).astype('float'))
据我所知，以这种方式处理numpy数组比循环遍历每个像素和使用colorsys要快得多。
现在，我偶然发现了一些将rgb转换为hsv的函数。 这有助于我生成具有不同色调的图像，但我还需要使用亮度，以便有些可以是黑色，有些可以是白色。
def rgb_to_hsv(rgb):
# Translated from source of colorsys.rgb_to_hsv
hsv=np.empty_like(rgb)
hsv[...,3:]=rgb[...,3:]
r,g,b=rgb[...,0],rgb[...,1],rgb[...,2]
maxc = np.max(rgb[...,:2],axis=-1)
minc = np.min(rgb[...,:2],axis=-1)
hsv[...,2] = maxc
hsv[...,1] = (maxc-minc) / maxc
rc = (maxc-r) / (maxc-minc)
gc = (maxc-g) / (maxc-minc)
bc = (maxc-b) / (maxc-minc)
hsv[...,0] = np.select([r==maxc,g==maxc],[bc-gc,2.0+rc-bc],default=4.0+gc-rc)
hsv[...,0] = (hsv[...,0]/6.0) % 1.0
idx=(minc == maxc)
hsv[...,0][idx]=0.0
hsv[...,1][idx]=0.0
return hsv
def hsv_to_rgb(hsv):
# Translated from source of colorsys.hsv_to_rgb
rgb=np.empty_like(hsv)
rgb[...,3:]=hsv[...,3:]
h,s,v=hsv[...,0],hsv[...,1],hsv[...,2]
i = (h*6.0).astype('uint8')
f = (h*6.0) - i
p = v*(1.0 - s)
q = v*(1.0 - s*f)
t = v*(1.0 - s*(1.0-f))
i = i%6
conditions=[s==0.0,i==1,i==2,i==3,i==4,i==5]
rgb[...,0]=np.select(conditions,[v,q,p,p,t,v],default=v)
rgb[...,1]=np.select(conditions,[v,v,v,q,p,p],default=t)
rgb[...,2]=np.select(conditions,[v,p,t,v,v,q],default=p)
return rgb
修改这些函数以转换为HSL和从HSL转换是多么容易？ 将HSV转换为HSL的任何技巧？
非常感谢您能给我的任何信息，谢谢！
答案 0 :(得分：1)
是的， numpy ，即矢量化代码，可以加快色彩转换。
对于10k +位图的大量生产越多，您可能希望重新使用现成的专业转换，或者如果它与您的首选亮度模型不完全匹配则重新使用它。
计算机视觉库OpenCV，目前可用作 cv2 模块的python，可以处理颜色系统转换，无需任何额外编码，只需：
out = cv2.cvtColor( anInputFRAME, cv2.COLOR_YUV2BGR ) # a bitmap conversion
cv2中提供的一些颜色系统列表（您可能会注意到 RGB 被称为 BRG 由于OpenCV惯例对图像的不同排序 B lue- R ed- G reen颜色平面，< / p>
（对称适用COLOR_YCR_CB2BGR＆lt; - | - ＆gt; COLOR_BGR2YCR_CB并非显示所有对）
>>> import cv2
>>> for key in dir( cv2 ): # show all ready conversions
... if key[:7] == 'COLOR_Y':
... print key
COLOR_YCR_CB2BGR
COLOR_YCR_CB2RGB
COLOR_YUV2BGR
COLOR_YUV2BGRA_I420
COLOR_YUV2BGRA_IYUV
COLOR_YUV2BGRA_NV12
COLOR_YUV2BGRA_NV21
COLOR_YUV2BGRA_UYNV
COLOR_YUV2BGRA_UYVY
COLOR_YUV2BGRA_Y422
COLOR_YUV2BGRA_YUNV
COLOR_YUV2BGRA_YUY2
COLOR_YUV2BGRA_YUYV
COLOR_YUV2BGRA_YV12
COLOR_YUV2BGRA_YVYU
COLOR_YUV2BGR_I420
COLOR_YUV2BGR_IYUV
COLOR_YUV2BGR_NV12
COLOR_YUV2BGR_NV21
COLOR_YUV2BGR_UYNV
COLOR_YUV2BGR_UYVY
COLOR_YUV2BGR_Y422
COLOR_YUV2BGR_YUNV
COLOR_YUV2BGR_YUY2
COLOR_YUV2BGR_YUYV
COLOR_YUV2BGR_YV12
COLOR_YUV2BGR_YVYU
COLOR_YUV2GRAY_420
COLOR_YUV2GRAY_I420
COLOR_YUV2GRAY_IYUV
COLOR_YUV2GRAY_NV12
COLOR_YUV2GRAY_NV21
COLOR_YUV2GRAY_UYNV
COLOR_YUV2GRAY_UYVY
COLOR_YUV2GRAY_Y422
COLOR_YUV2GRAY_YUNV
COLOR_YUV2GRAY_YUY2
COLOR_YUV2GRAY_YUYV
COLOR_YUV2GRAY_YV12
COLOR_YUV2GRAY_YVYU
COLOR_YUV2RGB
COLOR_YUV2RGBA_I420
COLOR_YUV2RGBA_IYUV
COLOR_YUV2RGBA_NV12
COLOR_YUV2RGBA_NV21
COLOR_YUV2RGBA_UYNV
COLOR_YUV2RGBA_UYVY
COLOR_YUV2RGBA_Y422
COLOR_YUV2RGBA_YUNV
COLOR_YUV2RGBA_YUY2
COLOR_YUV2RGBA_YUYV
COLOR_YUV2RGBA_YV12
COLOR_YUV2RGBA_YVYU
COLOR_YUV2RGB_I420
COLOR_YUV2RGB_IYUV
COLOR_YUV2RGB_NV12
COLOR_YUV2RGB_NV21
COLOR_YUV2RGB_UYNV
COLOR_YUV2RGB_UYVY
COLOR_YUV2RGB_Y422
COLOR_YUV2RGB_YUNV
COLOR_YUV2RGB_YUY2
COLOR_YUV2RGB_YUYV
COLOR_YUV2RGB_YV12
COLOR_YUV2RGB_YVYU
COLOR_YUV420P2BGR
COLOR_YUV420P2BGRA
COLOR_YUV420P2GRAY
COLOR_YUV420P2RGB
COLOR_YUV420P2RGBA
COLOR_YUV420SP2BGR
COLOR_YUV420SP2BGRA
COLOR_YUV420SP2GRAY
COLOR_YUV420SP2RGB
COLOR_YUV420SP2RGBA
我为Luminance转换做了一些原型设计（基于＆gt;＆gt;＆gt; http://en.wikipedia.org/wiki/HSL_and_HSV）
但未经测试发布。
def get_YUV_V_Cr_Rec601_BRG_frame( brgFRAME ): # For the Rec. 601 primaries used in gamma-corrected sRGB, fast, VECTORISED MUL/ADD CODE
out = numpy.zeros( brgFRAME.shape[0:2] )
out += 0.615 / 255 * brgFRAME[:,:,1] # // Red # normalise to <0.0 - 1.0> before vectorised MUL/ADD, saves [usec] ... on 480x640 [px] faster goes about 2.2 [msec] instead of 5.4 [msec]
out -= 0.515 / 255 * brgFRAME[:,:,2] # // Green
out -= 0.100 / 255 * brgFRAME[:,:,0] # // Blue # normalise to <0.0 - 1.0> before vectorised MUL/ADD
return out
答案 1 :(得分：0)
# -*- coding: utf-8 -*-
# @File : rgb2hls.py
# @Info : @ TSMC
# @Desc :
import colorsys
import numpy as np
import scipy.misc
import tensorflow as tf
from PIL import Image
def rgb2hls(img):
""" note: elements in img is a float number less than 1.0 and greater than 0.
:param img: an numpy ndarray with shape NHWC
:return:
"""
assert len(img.shape) == 3
hue = np.zeros_like(img[:, :, 0])
luminance = np.zeros_like(img[:, :, 0])
saturation = np.zeros_like(img[:, :, 0])
for x in range(height):
for y in range(width):
r, g, b = img[x, y]
h, l, s = colorsys.rgb_to_hls(r, g, b)
hue[x, y] = h
luminance[x, y] = l
saturation[x, y] = s
return hue, luminance, saturation
def np_rgb2hls(img):
r, g, b = img[:, :, 0], img[:, :, 1], img[:, :, 2]
maxc = np.max(img, -1)
minc = np.min(img, -1)
l = (minc + maxc) / 2.0
if np.array_equal(minc, maxc):
return np.zeros_like(l), l, np.zeros_like(l)
smask = np.greater(l, 0.5).astype(np.float32)
s = (1.0 - smask) * ((maxc - minc) / (maxc + minc)) + smask * ((maxc - minc) / (2.001 - maxc - minc))
rc = (maxc - r) / (maxc - minc + 0.001)
gc = (maxc - g) / (maxc - minc + 0.001)
bc = (maxc - b) / (maxc - minc + 0.001)
rmask = np.equal(r, maxc).astype(np.float32)
gmask = np.equal(g, maxc).astype(np.float32)
rgmask = np.logical_or(rmask, gmask).astype(np.float32)
h = rmask * (bc - gc) + gmask * (2.0 + rc - bc) + (1.0 - rgmask) * (4.0 + gc - rc)
h = np.remainder(h / 6.0, 1.0)
return h, l, s
def tf_rgb2hls(img):
""" note: elements in img all in [0,1]
:param img: a tensor with shape NHWC
:return:
"""
assert img.get_shape()[-1] == 3
r, g, b = img[:, :, 0], img[:, :, 1], img[:, :, 2]
maxc = tf.reduce_max(img, -1)
minc = tf.reduce_min(img, -1)
l = (minc + maxc) / 2.0
# if tf.reduce_all(tf.equal(minc, maxc)):
# return tf.zeros_like(l), l, tf.zeros_like(l)
smask = tf.cast(tf.greater(l, 0.5), tf.float32)
s = (1.0 - smask) * ((maxc - minc) / (maxc + minc)) + smask * ((maxc - minc) / (2.001 - maxc - minc))
rc = (maxc - r) / (maxc - minc + 0.001)
gc = (maxc - g) / (maxc - minc + 0.001)
bc = (maxc - b) / (maxc - minc + 0.001)
rmask = tf.equal(r, maxc)
gmask = tf.equal(g, maxc)
rgmask = tf.cast(tf.logical_or(rmask, gmask), tf.float32)
rmask = tf.cast(rmask, tf.float32)
gmask = tf.cast(gmask, tf.float32)
h = rmask * (bc - gc) + gmask * (2.0 + rc - bc) + (1.0 - rgmask) * (4.0 + gc - rc)
h = tf.mod(h / 6.0, 1.0)
h = tf.expand_dims(h, -1)
l = tf.expand_dims(l, -1)
s = tf.expand_dims(s, -1)
x = tf.concat([tf.zeros_like(l), l, tf.zeros_like(l)], -1)
y = tf.concat([h, l, s], -1)
return tf.where(condition=tf.reduce_all(tf.equal(minc, maxc)), x=x, y=y)
if __name__ == '__main__':
"""
HLS: Hue, Luminance, Saturation
H: position in the spectrum
L: color lightness
S: color saturation
"""
avatar = Image.open("hue.jpg")
width, height = avatar.size
print("width: {}, height: {}".format(width, height))
img = np.array(avatar)
img = img / 255.0
print(img.shape)
# # hue, luminance, saturation = rgb2hls(img)
# hue, luminance, saturation = np_rgb2hls(img)
img_tensor = tf.convert_to_tensor(img, tf.float32)
hls = tf_rgb2hls(img_tensor)
h, l, s = hls[:, :, 0], hls[:, :, 1], hls[:, :, 2]
with tf.Session() as sess:
sess.run(tf.global_variables_initializer())
hue, luminance, saturation = sess.run([h, l, s])
scipy.misc.imsave("hls_h_.jpg", hue)
scipy.misc.imsave("hls_l_.jpg", luminance)
scipy.misc.imsave("hls_s_.jpg", saturation)