How a Wuhan Student Used Python to Paint a Blooming Cherry Blossom from Pixels

After the COVID‑19 pandemic began to recede in China, Wuhan University opened a live broadcast of cherry blossoms, inviting people to enjoy spring online.

On March 18, a student from the School of Information Management, Zhu Yongchun, created a blooming cherry blossom entirely with Python code, using the phrase “武汉加油” (Wuhan, stay strong) as pixel elements.

The resulting image consists of many tiny characters, each representing a pixel whose color is defined by an RGB tuple.

Key steps of the program include:

Saving video frames as JPEG files with cv2.imwrite("pic/frame%d.jpg"%count, image).

Creating a blank RGB canvas and setting up a font with PIL:

blank = Image.new("RGB", [len(img[0]), len(img)], "white")
drawObj = ImageDraw.Draw(blank)
n = 10
font = ImageFont.truetype('C:/Windows/Fonts/Microsoft YaHei UI/msyhbd.ttc', size=n-1)

Then a nested loop iterates over the image pixels, assigns the pixel color to the drawing object, and writes the appropriate character:

for i in range(0, len(img), n):
    for j in range(0, len(img[i]), n):
        text = '武汉加油'
        drawObj.ink = img[i][j][0] + img[i][j][1]*256 + img[i][j][2]*256*256
        drawObj.text([j, i], text[int(j/n) % len(text)], font=font)
        print('完成处理——', i, j)
        blank.save('new/new_'+pic, 'jpeg')

Finally, the generated images are compiled into a video using OpenCV:

def picvideo(path, size):
    filelist = os.listdir(path)
    filelist = resort(filelist)
    fps = 24
    file_path = 'video/new.mp4'
    fourcc = cv2.VideoWriter_fourcc('D','I','V','X')
    video = cv2.VideoWriter(file_path, fourcc, fps, size)
    for item in filelist:
        if item.endswith('.jpg'):
            img = cv2.imread(path + '/' + item)
            video.write(img)
    video.release()

The complete source code is available for download, and the project demonstrates how thousands of “武汉加油” characters can be combined to form a blooming cherry blossom animation, symbolizing support for Wuhan.