Gradient#

This style uses Unicode characters.

Example

Consider the following image:

Apple Computer [Rob Janoff, 1977]

Here's what it should look like:

Procedure#

This style is implemented using the GradientDrawer.

Initialization#

Charset#

The charset parameter is a string containing characters ordered by their perceived brightness.

Consider the following image:

Here's what it should look like:

charset = ' :!?PG@' (default)

'.'

'#'

'█'

Negative#

The negative parameter controls whether the charset must be reversed.

Consider the following image:

Here's what it should look like:

negative = False

True

Matrices#

The charset_array attribute holds a NumPy ndarray containing all the characters in the charset.

Conversion#

Resizing#

Assuming the output text should have the dimensions text_height and text_width, the image must be resized according to the following criteria:

• image_height = text_height.
• image_width = text_width.
• If either image_height or image_width is 0, it is derived from the other by preserving the aspect ratio of the original image.

Following the above algorithm, each pixel of the resized image will be assigned to one character in the output text.

Processing#

1. The resized image is first converted to its grayscale.
2. The image matrix is normalized such that the grayscale range shifts from (0, 255) to (0, len(charset)).
3. The charset_array is indexed with the resultant "indices" matrix, giving the final text_matrix.