Image Processing of Food Labels

{saturated fat: 6.7g,
added sugar: 8.1g,
fibre: 8.5g,
proteins: 9.9g,
salt: 1.4g}
1estambolieva@gmail.com
Practical Image Processing

Social Entrepreneur
Huge Machine Learning
Enthusiast
ME

SUGARWISE
EXCEEDS
your daily allowance
of added sugar
try instead

THE PROBLEM

TESSERACT
https://github.com/tesseract-ocr

CONVERT TO GRAYSCALE
python: PIL libravy

PROBLEM: BINARIZATION
python: PIL library does not work here

colour histogram
~ 500 000 pixel values, each pixel value is a different colour

k-means clustering
image source: Wikipedia
http://stackoverflow.com/questions/3241929/python-find-dominant-most-common-color-in-an-image

kmeans: let's try it out
40x40 pixel window
"first window"

40x40 pixel window
"first window"
154

40x40 pixel window
"first window"

JPG v.s. PNG
40x40 pixel window

kmeans: results on full image

SOLUTION: sloppy way
colour (pixel values) histogram
find middle pixel value
everything below it goes black
everything above it goes white

SOLUTION: sloppy way

side to side comparison

LINE DELETION
work with windows or full image?
remove black regions > 400 pixels?
remove uninterrupted black
regions?
Are we missing something?

black regions > 400 pixels
window-wise

uninterrupted black regions
window-wise

SOLUTION: line detection
image-wise

SOLUTION: line detection
window-wise

line detection: untested
image-wise
fourier analysis

bonus: MIN FILTER
min filter PIL default: 3 pixels

bonus: SKELETON
python: openCV

CHALLENGE: WHITE PIXELS IN
LETTERS

THANKS!

More Related Content