Python - OpenCV - imread - 显示图像
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Python - OpenCV - imread - Displaying Image
提问by Sinjin Forde
I am currently working on reading an image and displaying it to a window. I have successfully done this, but upon displaying the image, the window only allows me to see a portion of the full image. I tried saving the image after loading it, and it saved the entire image. So I am fairly certain that it is reading the entire image.
我目前正在阅读图像并将其显示到窗口中。我已经成功地做到了这一点，但是在显示图像时，窗口只允许我看到完整图像的一部分。我在加载后尝试保存图像，它保存了整个图像。所以我相当确定它正在读取整个图像。
imgFile = cv.imread('1.jpg')
cv.imshow('dst_rt', imgFile)
cv.waitKey(0)
cv.destroyAllWindows()
Image:
图片：
Screenshot:
截屏：
采纳答案by Igonato
Looks like the image is too big and the window simply doesn't fit the screen.
Create window with the cv2.WINDOW_NORMALflag, it will make it scalable. Then you can resize it to fit your screen like this:
看起来图像太大，窗口根本不适合屏幕。创建带有cv2.WINDOW_NORMAL标志的窗口，它将使其具有可扩展性。然后你可以像这样调整它的大小以适合你的屏幕：
from __future__ import division
import cv2
img = cv2.imread('1.jpg')
screen_res = 1280, 720
scale_width = screen_res[0] / img.shape[1]
scale_height = screen_res[1] / img.shape[0]
scale = min(scale_width, scale_height)
window_width = int(img.shape[1] * scale)
window_height = int(img.shape[0] * scale)
cv2.namedWindow('dst_rt', cv2.WINDOW_NORMAL)
cv2.resizeWindow('dst_rt', window_width, window_height)
cv2.imshow('dst_rt', img)
cv2.waitKey(0)
cv2.destroyAllWindows()
According to the OpenCV documentationCV_WINDOW_KEEPRATIOflag should do the same, yet it doesn't and it's value not even presented in the python module.
根据 OpenCV 文档CV_WINDOW_KEEPRATIO标志应该做同样的事情，但它没有，它的值甚至没有出现在 python 模块中。
回答by Tom J Muthirenthi
This can help you
这可以帮助你
namedWindow( "Display window", CV_WINDOW_AUTOSIZE );// Create a window for display.
imshow( "Display window", image ); // Show our image inside it.
回答by Mahesh
In openCV whenever you try to display an oversized image or image bigger than your display resolution you get the cropped display. It's a default behaviour.
In order to view the image in the window of your choice openCV encourages to use named window. Please refer to namedWindow documentation
在 openCV 中，每当您尝试显示超大图像或大于显示分辨率的图像时，您都会得到裁剪的显示。这是默认行为。
为了在您选择的窗口中查看图像，openCV 鼓励使用命名窗口。请参考namedWindow文档
The function namedWindow creates a window that can be used as a placeholder for images and trackbars. Created windows are referred to by their names.
函数 namedWindow 创建一个窗口，可以用作图像和轨迹栏的占位符。创建的窗口以其名称引用。
cv.namedWindow(name, flags=CV_WINDOW_AUTOSIZE)where each window is related to image container by the name arg, make sure to use same name
cv.namedWindow(name, flags=CV_WINDOW_AUTOSIZE)其中每个窗口都通过名称 arg 与图像容器相关，请确保使用相同的名称
eg:
例如：
import cv2
frame = cv2.imread('1.jpg')
cv2.namedWindow("Display 1")
cv2.resizeWindow("Display 1", 300, 300)
cv2.imshow("Display 1", frame)
