Skip to content

Image Processing

Negative Film

An implementation of digital image processing to change RGB image or colormap to negative-film image.

Content

Requirements

  • Python
  • OpenCV 
    # apt-get install python-opencv

Programming

  • create file grayscale.py
import cv2

img=cv2.imread("../../lena.png")
height, width, channels = img.shape

print(height,width,channels)

for x in range(0,width):
    for y in range(0,height):      
        img[x,y,0] = 255 - img[x,y,0]
        img[x,y,1] = 255 - img[x,y,1]
        img[x,y,2] = 255 - img[x,y,2]

cv2.imwrite('lena_negative.png',img)

Running

Original Negative Film
r r

Observation

  • Observation by file command of Linux Shell
# file ../../lena.png
../../lena.png: PNG image data, 300 x 300, 8-bit/color RGB, non-interlaced

# file lena_negative.png
lena_negative.png: PNG image data, 300 x 300, 8-bit/color RGB, non-interlaced

Advanced

There are some packages which support Image Processing for Python also. User can test on it also. - scipy - Pygame - Numpy - pillow

Reference