Why does imshow display non-integer x and y values for the pixel position?
I am trying to read the x and y positions of the pixels in images. This is an example of what is shown when I run:
plt.figure(1)
plt.imshow(img)
plt.title('image')
plt.show()
Why are they non-integer values? My best guess is that some scaling is occurring? I am running python on spyder as an IDE.
Edit: Here is the image:
Edit 2: Upon closer inspection, inspecting pixel by pixel, they appear to be at the .5 marks rather than 0 to 1 as well. And here is a screenshot of my axis settings... something is definitely funky here. Anybody have an idea why?
python matplotlib imshow
asked Dec 27 '18 at 14:29
Daniel LuciDaniel Luci
404
add a comment |
I am trying to read the x and y positions of the pixels in images. This is an example of what is shown when I run:
plt.figure(1)
plt.imshow(img)
plt.title('image')
plt.show()
Why are they non-integer values? My best guess is that some scaling is occurring? I am running python on spyder as an IDE.
Edit: Here is the image:
Edit 2: Upon closer inspection, inspecting pixel by pixel, they appear to be at the .5 marks rather than 0 to 1 as well. And here is a screenshot of my axis settings... something is definitely funky here. Anybody have an idea why?
python matplotlib imshow
asked Dec 27 '18 at 14:29
Daniel LuciDaniel Luci
404
Sharing the image would help
– mk18
Dec 27 '18 at 21:11
1
@mk18 i have added the image
– Daniel Luci
Dec 28 '18 at 5:10
1
I believe it's because the plot is continuous, so while the pixels do have a size of 1 the sub-pixel region itself also has measurable space.
– Jack
Dec 28 '18 at 5:20
@Jack i updated with more photos
– Daniel Luci
Dec 28 '18 at 5:54
add a comment |
I am trying to read the x and y positions of the pixels in images. This is an example of what is shown when I run:
plt.figure(1)
plt.imshow(img)
plt.title('image')
plt.show()
Why are they non-integer values? My best guess is that some scaling is occurring? I am running python on spyder as an IDE.
Edit: Here is the image:
Edit 2: Upon closer inspection, inspecting pixel by pixel, they appear to be at the .5 marks rather than 0 to 1 as well. And here is a screenshot of my axis settings... something is definitely funky here. Anybody have an idea why?
python matplotlib imshow
asked Dec 27 '18 at 14:29
Daniel LuciDaniel Luci
404
I am trying to read the x and y positions of the pixels in images. This is an example of what is shown when I run:
plt.figure(1)
plt.imshow(img)
plt.title('image')
plt.show()
Why are they non-integer values? My best guess is that some scaling is occurring? I am running python on spyder as an IDE.
Edit: Here is the image:
Edit 2: Upon closer inspection, inspecting pixel by pixel, they appear to be at the .5 marks rather than 0 to 1 as well. And here is a screenshot of my axis settings... something is definitely funky here. Anybody have an idea why?
python matplotlib imshow
python matplotlib imshow
asked Dec 27 '18 at 14:29
Daniel LuciDaniel Luci
404
asked Dec 27 '18 at 14:29
Daniel LuciDaniel Luci
404
edited Dec 28 '18 at 5:53
Daniel Luci
asked Dec 27 '18 at 14:29
Daniel LuciDaniel Luci
404
asked Dec 27 '18 at 14:29
Daniel LuciDaniel Luci
404
asked Dec 27 '18 at 14:29
Daniel LuciDaniel Luci
404
404
Sharing the image would help
– mk18
Dec 27 '18 at 21:11
1
@mk18 i have added the image
– Daniel Luci
Dec 28 '18 at 5:10
1
I believe it's because the plot is continuous, so while the pixels do have a size of 1 the sub-pixel region itself also has measurable space.
– Jack
Dec 28 '18 at 5:20
@Jack i updated with more photos
– Daniel Luci
Dec 28 '18 at 5:54
add a comment |
Sharing the image would help
– mk18
Dec 27 '18 at 21:11
1
@mk18 i have added the image
– Daniel Luci
Dec 28 '18 at 5:10
1
I believe it's because the plot is continuous, so while the pixels do have a size of 1 the sub-pixel region itself also has measurable space.
– Jack
Dec 28 '18 at 5:20
@Jack i updated with more photos
– Daniel Luci
Dec 28 '18 at 5:54
Sharing the image would help
– mk18
Dec 27 '18 at 21:11
Sharing the image would help
– mk18
Dec 27 '18 at 21:11
1
1
@mk18 i have added the image
– Daniel Luci
Dec 28 '18 at 5:10
@mk18 i have added the image
– Daniel Luci
Dec 28 '18 at 5:10
1
1
I believe it's because the plot is continuous, so while the pixels do have a size of 1 the sub-pixel region itself also has measurable space.
– Jack
Dec 28 '18 at 5:20
I believe it's because the plot is continuous, so while the pixels do have a size of 1 the sub-pixel region itself also has measurable space.
– Jack
Dec 28 '18 at 5:20
@Jack i updated with more photos
– Daniel Luci
Dec 28 '18 at 5:54
@Jack i updated with more photos
– Daniel Luci
Dec 28 '18 at 5:54
add a comment |
1 Answer
1
active
oldest
votes
My guess is, that the float values you worry about while hovering over the shown image with your mouse is just the mouse pointer position, which does not have to be integer. Yet still lays within a pixel (squared integer area) and thus gives you information about the channels at that pixel's position.
Another way to get information about your pixels in a more controlled way is given here:
Here is my working code snippet printing the pixel colours from an image:
import os, sys
import Image
im = Image.open("image.jpg")
x = 3
y = 4
pix = im.load()
print pix[x,y]
Answer edit 2: It just makes sense like that. The pixel centers fall on the integer values .0 you expect the pixels to have. If the edges would fall on the .0 a direct mapping between pixel coordinates and pixel values would not be possible within the visualization. Also the pixel having a height and width of 1 is exactly what we would expect.
answered Dec 28 '18 at 5:22
mk18mk18
1,94611330
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
My guess is, that the float values you worry about while hovering over the shown image with your mouse is just the mouse pointer position, which does not have to be integer. Yet still lays within a pixel (squared integer area) and thus gives you information about the channels at that pixel's position.
Another way to get information about your pixels in a more controlled way is given here:
Here is my working code snippet printing the pixel colours from an image:
import os, sys
import Image
im = Image.open("image.jpg")
x = 3
y = 4
pix = im.load()
print pix[x,y]
Answer edit 2: It just makes sense like that. The pixel centers fall on the integer values .0 you expect the pixels to have. If the edges would fall on the .0 a direct mapping between pixel coordinates and pixel values would not be possible within the visualization. Also the pixel having a height and width of 1 is exactly what we would expect.
answered Dec 28 '18 at 5:22
mk18mk18
1,94611330
add a comment |
My guess is, that the float values you worry about while hovering over the shown image with your mouse is just the mouse pointer position, which does not have to be integer. Yet still lays within a pixel (squared integer area) and thus gives you information about the channels at that pixel's position.
Another way to get information about your pixels in a more controlled way is given here:
Here is my working code snippet printing the pixel colours from an image:
import os, sys
import Image
im = Image.open("image.jpg")
x = 3
y = 4
pix = im.load()
print pix[x,y]
Answer edit 2: It just makes sense like that. The pixel centers fall on the integer values .0 you expect the pixels to have. If the edges would fall on the .0 a direct mapping between pixel coordinates and pixel values would not be possible within the visualization. Also the pixel having a height and width of 1 is exactly what we would expect.
answered Dec 28 '18 at 5:22
mk18mk18
1,94611330
add a comment |
My guess is, that the float values you worry about while hovering over the shown image with your mouse is just the mouse pointer position, which does not have to be integer. Yet still lays within a pixel (squared integer area) and thus gives you information about the channels at that pixel's position.
Another way to get information about your pixels in a more controlled way is given here:
Here is my working code snippet printing the pixel colours from an image:
import os, sys
import Image
im = Image.open("image.jpg")
x = 3
y = 4
pix = im.load()
print pix[x,y]
Answer edit 2: It just makes sense like that. The pixel centers fall on the integer values .0 you expect the pixels to have. If the edges would fall on the .0 a direct mapping between pixel coordinates and pixel values would not be possible within the visualization. Also the pixel having a height and width of 1 is exactly what we would expect.
answered Dec 28 '18 at 5:22
mk18mk18
1,94611330
My guess is, that the float values you worry about while hovering over the shown image with your mouse is just the mouse pointer position, which does not have to be integer. Yet still lays within a pixel (squared integer area) and thus gives you information about the channels at that pixel's position.
Another way to get information about your pixels in a more controlled way is given here:
Here is my working code snippet printing the pixel colours from an image:
import os, sys
import Image
im = Image.open("image.jpg")
x = 3
y = 4
pix = im.load()
print pix[x,y]
Answer edit 2: It just makes sense like that. The pixel centers fall on the integer values .0 you expect the pixels to have. If the edges would fall on the .0 a direct mapping between pixel coordinates and pixel values would not be possible within the visualization. Also the pixel having a height and width of 1 is exactly what we would expect.
answered Dec 28 '18 at 5:22
mk18mk18
1,94611330
edited Dec 28 '18 at 6:29
answered Dec 28 '18 at 5:22
mk18mk18
1,94611330
answered Dec 28 '18 at 5:22
mk18mk18
1,94611330
answered Dec 28 '18 at 5:22
mk18mk18
1,94611330
1,94611330
add a comment |
add a comment |
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Sharing the image would help
– mk18
Dec 27 '18 at 21:11
1
@mk18 i have added the image
– Daniel Luci
Dec 28 '18 at 5:10
1
I believe it's because the plot is continuous, so while the pixels do have a size of 1 the sub-pixel region itself also has measurable space.
– Jack
Dec 28 '18 at 5:20
@Jack i updated with more photos
– Daniel Luci
Dec 28 '18 at 5:54