03. Image as data

Image as data

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Prerequisites

python
RGB

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1. What is Image

On computer vision, image is a set of numeric data. As viusalized, the image is very intuitive, however when we process images, we should approach image as data.

Bascially, Image has features as follows:

(W, H, C)

width
height
channel

pixel

byte type per pixel

2. How to read image

st_image.py

import cv2 as cv
import os

def getDataPath():
    strRoot = os.getcwd()
    strDir = os.path.join(strRoot, "data")
    return strDir

def getDataPathWithFile(path):
    strImage = os.path.join(getDataPath(), path)
    return strImage

def readImage(path):
    img = cv.imread(path)
    return img

def showImage(title, img):
    cv.imshow(title, img)
    cv.waitKey(0)
    cv.destroyAllWindows()
    
def writeImage(path, img):
    cv.imwrite(path, img)

main.py

import cv2 as cv
import os
import st_image

if __name__ == "__main__":
    img = st_image.readImage(st_image.getDataPathWithFile("cat.png"))
    st_image.showImage("Cat", img)
    st_image.writeImage(st_image.getDataPathWithFile("cat_copy.png"), img)