對(duì)比測(cè)試 scipy.misc 和 PIL.Image 和 libtiff.TIFF 三個(gè)庫(kù)
輸入:
1. (讀取矩陣) 讀入uint8、uint16、float32的lena.tif
2. (生成矩陣) 使用numpy產(chǎn)生隨機(jī)矩陣,float64的mat
import numpy as npfrom scipy import miscfrom PIL import Imagefrom libtiff import TIFF ## 讀入已有圖像,數(shù)據(jù)類型和原圖像一致tif32 = misc.imread('./test/lena32.tif') #<class 'numpy.float32'>tif16 = misc.imread('./test/lena16.tif') #<class 'numpy.uint16'>tif8 = misc.imread('./test/lena8.tif') #<class 'numpy.uint8'># 產(chǎn)生隨機(jī)矩陣,數(shù)據(jù)類型float64np.random.seed(12345)flt = np.random.randn(512, 512) #<class 'numpy.float64'># 轉(zhuǎn)換float64矩陣type,為后面作測(cè)試z8 = (flt.astype(np.uint8)) #<class 'numpy.uint8'>z16 = (flt.astype(np.uint16)) #<class 'numpy.uint16'>z32 = (flt.astype(np.float32)) #<class 'numpy.float32'> ①對(duì)讀取圖像和隨機(jī)矩陣的存儲(chǔ)
# scipy.misc『不論輸入數(shù)據(jù)是何類型,輸出圖像均為uint8』misc.imsave('./test/lena32_scipy.tif', tif32) #--> 8bit(tif16和tif8同)misc.imsave('./test//randmat64_scipy.tif', flt) #--> 8bitmisc.imsave('./test//randmat8_scipy.tif', z8) #--> 8bit(z16和z32同)# PIL.Image『8位16位輸出圖像與輸入數(shù)據(jù)類型保持一致,64位會(huì)存成32位』Image.fromarray(tif32).save('./test/lena32_Image.tif') #--> 32bitImage.fromarray(tif16).save('./test/lena16_Image.tif') #--> 16bitImage.fromarray(tif8).save('./test/lena8_Image.tif') #--> 8bitImage.fromarray(flt).save('./test//randmat_Image.tif') #--> 32bit(flt.min~flt.max)im = Image.fromarray(flt.astype(np.float32)) im.save('./test//randmat32_Image.tif') #--> 32bit(灰度值范圍同上)#『uint8和uint16類型轉(zhuǎn)換,會(huì)使輸出圖像灰度變換到255和65535』im = Image.frombytes('I;16', (512, 512), flt.tostring())im.save('./test//randmat16_Image1.tif') #--> 16bit(0~65535)im = Image.fromarray(flt.astype(np.uint16)) im.save('./test//randmat16_Image2.tif') #--> 16bit(0~65535)im = Image.fromarray(flt.astype(np.uint8)) im.save('./test//randmat8_Image.tif') #--> 8bit(0~255)# libtiff.TIFF『輸出圖像與輸入數(shù)據(jù)類型保持一致』tif = TIFF.open('./test//randmat_TIFF.tif', mode='w') tif.write_image(flt, compression=None)tif.close() #float64可以存儲(chǔ),但因BitsPerSample=64,一些圖像軟件不識(shí)別tif = TIFF.open('./test//randmat32_TIFF.tif', mode='w') tif.write_image(flt.astype(np.float32), compression=None)tif.close() #--> 32bit(flt.min~flt.max)#『uint8和uint16類型轉(zhuǎn)換,會(huì)使輸出圖像灰度變換到255和65535』tif = TIFF.open('./test//randmat16_TIFF.tif', mode='w') tif.write_image(flt.astype(np.uint16), compression=None)tif.close() #--> 16bit(0~65535,8位則0~255)②圖像或矩陣歸一化對(duì)存儲(chǔ)的影響
# 『使用scipy,只能存成uint8』z16Norm = (z16-np.min(z16))/(np.max(z16)-np.min(z16)) #<class 'numpy.float64'>z32Norm = (z32-np.min(z32))/(np.max(z32)-np.min(z32))scipy.misc.imsave('./test//randmat16_norm_scipy.tif', z16Norm) #--> 8bit(0~255)# 『使用Image,歸一化后變成np.float64 直接轉(zhuǎn)8bit或16bit都會(huì)超出閾值,要*255或*65535』# 『如果沒(méi)有astype的位數(shù)設(shè)置,float64會(huì)直接存成32bit』im = Image.fromarray(z16Norm)im.save('./test//randmat16_norm_Image.tif') #--> 32bit(0~1)im = Image.fromarray(z16Norm.astype(np.float32))im.save('./test//randmat16_norm_to32_Image.tif') #--> 32bit(灰度范圍值同上)im = Image.fromarray(z16Norm.astype(np.uint16))im.save('./test//randmat16_norm_to16_Image.tif') #--> 16bit(0~1)超出閾值im = Image.fromarray(z16Norm.astype(np.uint8))im.save('./test//randmat16_norm_to8_Image.tif') #--> 8bit(0~1)超出閾值im = Image.fromarray((z16Norm*65535).astype(np.uint16))im.save('./test//randmat16_norm_to16_Image1.tif') #--> 16bit(0~65535)im = Image.fromarray((z16Norm*255).astype(np.uint16))im.save('./test//randmat16_norm_to16_Image2.tif') #--> 16bit(0~255)im = Image.fromarray((z16Norm*255).astype(np.uint8))im.save('./test//randmat16_norm_to8_Image2.tif') #--> 8bit(0~255)# 『使用TIFF結(jié)果同Image』③TIFF讀取和存儲(chǔ)多幀tiff圖像
#tiff文件解析成圖像序列:讀取tiff圖像def tiff_to_read(tiff_image_name): tif = TIFF.open(tiff_image_name, mode = "r") im_stack = list() for im in list(tif.iter_images()): im_stack.append(im) return #根據(jù)文檔,應(yīng)該是這樣實(shí)現(xiàn),但測(cè)試中不管是tif.read_image還是tif.iter_images讀入的矩陣數(shù)值都有問(wèn)題#圖像序列保存成tiff文件:保存tiff圖像 def write_to_tiff(tiff_image_name, im_array, image_num): tif = TIFF.open(tiff_image_name, mode = 'w') for i in range(0, image_num): im = Image.fromarray(im_array[i]) #縮放成統(tǒng)一尺寸 im = im.resize((480, 480), Image.ANTIALIAS) tif.write_image(im, compression = None) out_tiff.close() return
補(bǔ)充:libtiff讀取多幀tiff圖像
因?yàn)門IFF.open().read_image()和TIFF.open().iter_images()有問(wèn)題,則換一種方式讀
from libtiff import TIFFfiletif = TIFFfile('./test/lena32-3.tif')samples, _ = tif.get_samples()以上這篇淺談python下tiff圖像的讀取和保存方法就是小編分享給大家的全部?jī)?nèi)容了,希望能給大家一個(gè)參考,也希望大家多多支持VEVB武林網(wǎng)。
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