# Image Pre-processing

1. Invert image - Tesseract 3.0 only?
2. Rescale
3. Binarize
4. Remove noise
5. Dilation and erosion
6. Rotation and deskewing
7. Remove borders
8. Missing borders
9. Transparency and alpha channel

## Invert Image

```python
inverted_image = cv2.bitwise_not(image)
cv2.imwrite('tmp/inverted_image.jpg', inverted_image)
```

## Rescale

## Binarize

1. Grayscale image first.
2. Convert to black and white.
    * Adjust threshold values, may require testing.

## Remove Noise