# Picture to character drawing in Python, so easy!

2022-06-24 07:50:19

author | Parson sauce

source | Python technology

I believe you often see people show all kinds of character paintings on the Internet , For this colorful world , What we see everyday are some high-definition color pictures , Occasionally a rough black-and-white character painting , It's quite relaxing .

### Principle of character drawing

The principle of this character painting is also relatively simple , We can think of each character as a large pixel , A character can represent a color , The more characters , The more colors you can reflect , Character painting is more hierarchical .

#### Gray value and RGB

The gray value refers to the depth of the color at the point of the black-and-white image , Its scope is 0-255, White is 255, Black is 0, Other colors are somewhere in between .

RGB It's red, green and blue , Other colors can be obtained through different superposition .

To convert a picture to a character drawing , You need to define a character set first , Used for mapping with gray values , The image of each pixel RGB Value is converted to a grayscale value , Output the corresponding character to get the character drawing .

RGB To gray value , There is a transformational formula , Source network ：

gray = (2126 * r + 7152 * g + 722 * b) / 10000

### Code combat

I chose a picture at random ：

My goal is to transform into the following ：

According to the above conversion principle , Let's go straight to the code ：

``````from PIL import Image

char = list('M3NB6Q#OC?7>!:–;. ')

def get_char(r, g, b, alpha=256):
if alpha == 0:
return ' '

grey = (2126 * r + 7152 * g + 722 * b) / 10000

char_idx = int((grey / (alpha + 1.0)) * len(char))
return char[char_idx]

def write_file(out_file_name, content):
with open(out_file_name, 'w') as f:
f.write(content)

def main(file_name="input.jpg", width=100, height=80, out_file_name='output.txt'):
text = ''
im = Image.open(file_name)
im = im.resize((width, height), Image.NEAREST)
for i in range(height):
for j in range(width):
text += get_char(*im.getpixel((j, i)))
text += '\n'
print(text)
write_file(out_file_name, text)

if __name__ == '__main__':
main('dance.png')``````

The idea of procedure ：

• Defines an array of characters , The characters in this array can be written at will .

• Resolution images , Parse each pixel in the picture into RGB value .

• According to our above formula , Convert each pixel into a character in the character array .

• Concatenate the characters corresponding to all pixels , The conversion is complete .

### summary

Picture to character , The principle and idea of transformation are relatively simple , The implementation is not complicated , You can try it ！

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