opencv - 使用 mogrify 进行 jpg 到 png 的无损转换
问题描述
我正在尝试jpg
使用png
. mogrify
为了得到这个结果,我使用了这个命令:
mogrify -format png test.jpeg
但是,检查两个图像是否相同的测试失败。要执行测试,我使用此python
脚本:
import cv2
jpg_image = cv2.imread("test.jpeg")
png_image = cv2.imread("test.png")
diff = jpg_image - png_image
cv2.imshow("diff", diff)
cv2.waitKey(0)
cv2.closeAllWindows()
如果两个图像相同,则此脚本的执行会显示一个黑色矩形。
我尝试使用它进行转换opencv
并且它有效。这是python
我用来获得结果的脚本opencv
:
import cv2
jpg_image = cv2.imread("/home/roberto/Downloads/index.jpeg")
cv2.imwrite("/home/roberto/Downloads/index.png", jpg_image)
正如下面评论中所建议的,我还对由和生成的文件运行了该identify -verbose
命令。这些是输出:png
mogrify
opencv
mogrify
Image: index.png24
Format: PNG (Portable Network Graphics)
Mime type: image/png
Class: DirectClass
Geometry: 276x183+0+0
Units: Undefined
Type: TrueColor
Endianess: Undefined
Colorspace: sRGB
Depth: 8-bit
Channel depth:
red: 8-bit
green: 8-bit
blue: 8-bit
Channel statistics:
Pixels: 50508
Red:
min: 0 (0)
max: 153 (0.6)
mean: 19.2985 (0.0756804)
standard deviation: 16.1262 (0.06324)
kurtosis: 4.912
skewness: 1.86378
entropy: 0.805148
Green:
min: 0 (0)
max: 176 (0.690196)
mean: 64.9359 (0.254651)
standard deviation: 45.101 (0.176867)
kurtosis: -0.895497
skewness: 0.554883
entropy: 0.968001
Blue:
min: 0 (0)
max: 255 (1)
mean: 144.46 (0.566511)
standard deviation: 50.6283 (0.198542)
kurtosis: -0.289594
skewness: -0.566585
entropy: 0.950031
Image statistics:
Overall:
min: 0 (0)
max: 255 (1)
mean: 76.2316 (0.298948)
standard deviation: 40.2384 (0.157798)
kurtosis: 11.4068
skewness: 2.70212
entropy: 0.907726
Rendering intent: Perceptual
Gamma: 0.45455
Chromaticity:
red primary: (0.64,0.33)
green primary: (0.3,0.6)
blue primary: (0.15,0.06)
white point: (0.3127,0.329)
Background color: white
Border color: srgb(223,223,223)
Matte color: grey74
Transparent color: black
Interlace: None
Intensity: Undefined
Compose: Over
Page geometry: 276x183+0+0
Dispose: Undefined
Iterations: 0
Compression: Zip
Orientation: Undefined
Properties:
date:create: 2019-03-21T09:51:42+01:00
date:modify: 2019-03-21T09:51:42+01:00
png:bKGD: chunk was found (see Background color, above)
png:cHRM: chunk was found (see Chromaticity, above)
png:gAMA: gamma=0.45454544 (See Gamma, above)
png:IHDR.bit-depth-orig: 8
png:IHDR.bit_depth: 8
png:IHDR.color-type-orig: 2
png:IHDR.color_type: 2 (Truecolor)
png:IHDR.interlace_method: 0 (Not interlaced)
png:IHDR.width,height: 276, 183
png:sRGB: intent=0 (Perceptual Intent)
png:text: 2 tEXt/zTXt/iTXt chunks were found
signature: 1bdb735da64a7036eb46f2d257997fbd10044ddc633c2aea5703f1887614709c
Artifacts:
filename: index-mogrify.png
verbose: true
Tainted: False
Filesize: 79.9KB
Number pixels: 50.5K
User time: 0.000u
Elapsed time: 0:01.000
Version: ImageMagick 6.9.7-4 Q16 x86_64 20170114 http://www.imagemagick.org
opencv
:
Image: index-opencv.png
Format: PNG (Portable Network Graphics)
Mime type: image/png
Class: DirectClass
Geometry: 276x183+0+0
Units: Undefined
Type: TrueColor
Endianess: Undefined
Colorspace: sRGB
Depth: 8-bit
Channel depth:
red: 8-bit
green: 8-bit
blue: 8-bit
Channel statistics:
Pixels: 50508
Red:
min: 0 (0)
max: 153 (0.6)
mean: 19.299 (0.0756825)
standard deviation: 16.1246 (0.0632336)
kurtosis: 4.91164
skewness: 1.86412
entropy: 0.80384
Green:
min: 0 (0)
max: 175 (0.686275)
mean: 64.9195 (0.254586)
standard deviation: 45.064 (0.176722)
kurtosis: -0.898132
skewness: 0.553704
entropy: 0.968909
Blue:
min: 0 (0)
max: 255 (1)
mean: 144.561 (0.566908)
standard deviation: 50.7463 (0.199005)
kurtosis: -0.296128
skewness: -0.559014
entropy: 0.950698
Image statistics:
Overall:
min: 0 (0)
max: 255 (1)
mean: 76.26 (0.299059)
standard deviation: 40.2739 (0.157937)
kurtosis: 11.4583
skewness: 2.7144
entropy: 0.907815
Rendering intent: Perceptual
Gamma: 0.454545
Chromaticity:
red primary: (0.64,0.33)
green primary: (0.3,0.6)
blue primary: (0.15,0.06)
white point: (0.3127,0.329)
Background color: white
Border color: srgb(223,223,223)
Matte color: grey74
Transparent color: black
Interlace: None
Intensity: Undefined
Compose: Over
Page geometry: 276x183+0+0
Dispose: Undefined
Iterations: 0
Compression: Zip
Orientation: Undefined
Properties:
date:create: 2019-03-21T09:50:20+01:00
date:modify: 2019-03-21T09:50:20+01:00
png:IHDR.bit-depth-orig: 8
png:IHDR.bit_depth: 8
png:IHDR.color-type-orig: 2
png:IHDR.color_type: 2 (Truecolor)
png:IHDR.interlace_method: 0 (Not interlaced)
png:IHDR.width,height: 276, 183
png:sRGB: intent=0 (Perceptual Intent)
signature: 217fe60358faf232f04ccc66dd92ec508fbf82b37858f0b954c87372720b88a1
Artifacts:
filename: index-opencv.png
verbose: true
Tainted: False
Filesize: 89.3KB
Number pixels: 50.5K
User time: 0.000u
Elapsed time: 0:01.000
Version: ImageMagick 6.9.7-4 Q16 x86_64 20170114 http://www.imagemagick.org
mogirfy
有人可以解释一下第一种和第二种方法( vs opencv
)之间的区别吗?
解决方案
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