Filling Array is Slow
up vote
0
down vote
favorite
The code below is a project that I am working on to eventually analyze some images but right now I am purely trying to read an image and convert it to black and white. The input should be either white or something else which would end up as black so it is easy to check for this.
import matplotlib.pyplot as plt
import matplotlib.image as mpimg
import numpy as np
img = mpimg.imread('./Training/Image1.png')
imgplot = plt.imshow(img)
width = img.shape[1]
height = img.shape[0]
def generateArray():
arr =
for y in range(img.shape[0]):
arr.append()
for x in range(img.shape[1]):
if img[y][x][0] != 1:
arr[y].append(1)
else:
arr[y].append(0)
return arr
arr = generateArray()
plt.show()
To be clear, I desire to create an array arr that contains either a 0 if the corresponding pixel in the inputted image is white or 1 if it is anything other than white.
I am somewhat of a beginner with Python but I am confused as to why this code takes so long to run (>19 seconds on my older mac). Is there something that I am missing that would speed it up significantly?
python performance
asked 11 mins ago
dalearn
1113
add a comment |
up vote
0
down vote
favorite
The code below is a project that I am working on to eventually analyze some images but right now I am purely trying to read an image and convert it to black and white. The input should be either white or something else which would end up as black so it is easy to check for this.
import matplotlib.pyplot as plt
import matplotlib.image as mpimg
import numpy as np
img = mpimg.imread('./Training/Image1.png')
imgplot = plt.imshow(img)
width = img.shape[1]
height = img.shape[0]
def generateArray():
arr =
for y in range(img.shape[0]):
arr.append()
for x in range(img.shape[1]):
if img[y][x][0] != 1:
arr[y].append(1)
else:
arr[y].append(0)
return arr
arr = generateArray()
plt.show()
To be clear, I desire to create an array arr that contains either a 0 if the corresponding pixel in the inputted image is white or 1 if it is anything other than white.
I am somewhat of a beginner with Python but I am confused as to why this code takes so long to run (>19 seconds on my older mac). Is there something that I am missing that would speed it up significantly?
python performance
asked 11 mins ago
dalearn
1113
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
The code below is a project that I am working on to eventually analyze some images but right now I am purely trying to read an image and convert it to black and white. The input should be either white or something else which would end up as black so it is easy to check for this.
import matplotlib.pyplot as plt
import matplotlib.image as mpimg
import numpy as np
img = mpimg.imread('./Training/Image1.png')
imgplot = plt.imshow(img)
width = img.shape[1]
height = img.shape[0]
def generateArray():
arr =
for y in range(img.shape[0]):
arr.append()
for x in range(img.shape[1]):
if img[y][x][0] != 1:
arr[y].append(1)
else:
arr[y].append(0)
return arr
arr = generateArray()
plt.show()
To be clear, I desire to create an array arr that contains either a 0 if the corresponding pixel in the inputted image is white or 1 if it is anything other than white.
I am somewhat of a beginner with Python but I am confused as to why this code takes so long to run (>19 seconds on my older mac). Is there something that I am missing that would speed it up significantly?
python performance
asked 11 mins ago
dalearn
1113
The code below is a project that I am working on to eventually analyze some images but right now I am purely trying to read an image and convert it to black and white. The input should be either white or something else which would end up as black so it is easy to check for this.
import matplotlib.pyplot as plt
import matplotlib.image as mpimg
import numpy as np
img = mpimg.imread('./Training/Image1.png')
imgplot = plt.imshow(img)
width = img.shape[1]
height = img.shape[0]
def generateArray():
arr =
for y in range(img.shape[0]):
arr.append()
for x in range(img.shape[1]):
if img[y][x][0] != 1:
arr[y].append(1)
else:
arr[y].append(0)
return arr
arr = generateArray()
plt.show()
To be clear, I desire to create an array arr that contains either a 0 if the corresponding pixel in the inputted image is white or 1 if it is anything other than white.
I am somewhat of a beginner with Python but I am confused as to why this code takes so long to run (>19 seconds on my older mac). Is there something that I am missing that would speed it up significantly?
python performance
python performance
asked 11 mins ago
dalearn
1113
asked 11 mins ago
dalearn
1113
asked 11 mins ago
dalearn
1113
asked 11 mins ago
dalearn
1113
asked 11 mins ago
dalearn
1113
1113
add a comment |
add a comment |
active
oldest
votes
Your Answer
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["\$", "\$"]]);
});
});
}, "mathjax-editing");
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "196"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodereview.stackexchange.com%2fquestions%2f209952%2ffilling-array-is-slow%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
active
oldest
votes
active
oldest
votes
active
oldest
votes
active
oldest
votes
Thanks for contributing an answer to Code Review Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodereview.stackexchange.com%2fquestions%2f209952%2ffilling-array-is-slow%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
