How to create text in a python image?

Question

I wanted to create a text in an image, with python, to show a variable (whatever the format), e.g.: i have an image showing an A = 0, then I change a variable, refocus the image and it appears A = 15, it’s like I do something like?

Answer 1

There are several ways to do it. You can use the package PIL (Python Image Library), can use the package matplotlib, can use the package scikit-image and so on. You can also use screen creation packages (the Pyqt comes to mind - and if your intention is to build a graphical interface, this is the best approach). Anyway, you have many options.

Despite the Opencv be something useful for far more convoluted things, I find his approach to creating images very simple. Here’s an example of code:

import numpy as np
import cv2

def mostraVariavel(nome, valor):
    # Cria uma imagem nova (tamanho 400x200 e 3 canais RGB)
    largura = 400
    altura = 200
    imagem = np.zeros((altura, largura, 3), dtype=np.uint8)

    # Preenche o fundo de amarelo
    cv2.rectangle(imagem, (0, 0), (largura, altura), (0, 255, 255), -1)

    # Desenha uma borda azul
    cv2.rectangle(imagem, (0, 0), (largura-5, altura-5), (255, 0, 0), 5)

    # Desenha o texto com a variavel em preto, no centro
    texto = '{} = {}'.format(nome, valor)

    fonte = cv2.FONT_HERSHEY_SCRIPT_SIMPLEX
    escala = 2
    grossura = 3

    # Pega o tamanho (altura e largura) do texto em pixels
    tamanho, _ = cv2.getTextSize(texto, fonte, escala, grossura)

    # Desenha o texto no centro
    cv2.putText(imagem, texto, (int(largura / 2 - tamanho[0] / 2), int(altura / 2 + tamanho[1] / 2)), fonte, escala, (0, 0, 0), grossura)

    # Exibe a imagem
    cv2.imshow("Imagem", imagem)
    cv2.waitKey(0)

if __name__ == '__main__':
    a = 15
    mostraVariavel('a', a)

Which produces the following result: