Question

from numpy import mean,cov,cumsum,dot,linalg,size,flipud
import numpy as np
from pylab import imread,subplot,imshow,title,gray,figure,show,NullLocator

def princomp(A,numpc=0):
    #computing eigenvalues and eigenvectors of covariance matrix
    M = (A-mean(A.T,axis=1)).T # subtract the mean (along columns)
    [latent,coeff] = linalg.eig(cov(M))
    p = size(coeff,axis=1)
    idx = np.argsort(latent) # sorting the eigenvalues
    idx = idx[::-1]       # in ascending order
 #sorting eigenvectors according to the sorted eigenvalues
    coeff = coeff[:,idx]
    latent = latent[idx] # sorting eigenvalues
    if numpc < p and numpc >= 0:
         coeff = coeff[:,range(numpc)] # cutting some PCs if needed
    score = dot(coeff.T,M) # projection of the data in the new space
    return coeff,score,latent

A = imread('beatles.jpg') # load an image
A = mean(A,2) # to get a 2-D array
full_pc = size(A,axis=1) # numbers of all the principal components
i = 1
dist = []
for numpc in range(0,full_pc+10,10): # 0 10 20 ... full_pc
    coeff, score, latent = princomp(A,numpc)
    Ar = dot(coeff,score).T+mean(A,axis=0) # image reconstruction
    # difference in Frobenius norm
    dist.append(linalg.norm(A-Ar,'fro'))
    # showing the pics reconstructed with less than 50 PCs
    if numpc <= 50:
        ax = subplot(2,3,i,frame_on=False)
        ax.xaxis.set_major_locator(NullLocator()) # remove ticks
        ax.yaxis.set_major_locator(NullLocator())
        i += 1 
        imshow(flipud(Ar))
        title('PCs # '+str(numpc))
        gray()

figure()
imshow(flipud(A))
title('numpc FULL')
gray()
show()

错误如上所示。这是我在网上找到的关于PCA图像压缩的示例代码。建议会有所帮助。整个错误是：

Traceback (most recent call last):
  File "try.py", line 36, in <module>
    imshow(flipud(Ar))
  File "/home/user/.virtualenvs/cv/local/lib/python3.5/site-packages/matplotlib/pyplot.py", line 3157, in imshow
    **kwargs)
  File "/home/user/.virtualenvs/cv/local/lib/python3.5/site-packages/matplotlib/__init__.py", line 1898, in inner
    return func(ax, *args, **kwargs)
  File "/home/user/.virtualenvs/cv/local/lib/python3.5/site-packages/matplotlib/axes/_axes.py", line 5124, in imshow
    im.set_data(X)
  File "/home/user/.virtualenvs/cv/local/lib/python3.5/site-packages/matplotlib/image.py", line 596, in set_data
    raise TypeError("Image data can not convert to float")
TypeError: Image data can not convert to float

Answer 1

您无法使用matplotlib Ar = dot(coeff,score).T+mean(A,axis=0) # image reconstruction Ar = Ar.real绘制复杂数组。因此，您需要单独使用实部或虚部，例如

low_price_low_stock_goods

TypeError：图像数据无法转换为float。如何缓解此错误？

1 个答案: