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??Numpy???????????????

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?????Numpy??????????????

import numpy as np
from PIL import Image
def loadImage(file_path):
    """????????????"""
    return np.array(Image.open(file_path).convert('L'))
def saveImage(file_path, img):
    """????????BMP??"""
    im = Image.fromarray(img).convert('L')
    im.save(file_path)
def transform(img, c=1, a=0):
    """??????"""
    gNew = np.zeros(img.shape, dtype=img.dtype)
    w, h = img.shape
    for i in range(w):
        for j in range(h):
            gNew[i][j] = min(int(c * img[i][j] + a), 255)
    return gNew
def transform1(img, c=2.42, a=0):
    """???????"""
    dst = np.zeros_like(img).astype(np.float32)
    dst = c * img.astype(np.float32) + a
    dst = np.clip(dst, 0, 255).astype(img.dtype)
    return dst
# ??????
img = loadImage('test.png')
plt.imshow(img, cmap='gray')
# ????
imgNew = transform1(img, 2.42, 0)
# ????
plt.imshow(imgNew, cmap='gray')
saveImage('out-A.bmp', imgNew)

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def nonLinearTransform(img, power=0.5, contrast=2.0):
    """???????"""
    # ??S?????????
    gray = img.astype(np.float32)
    max_val = np.max(gray)
    min_val = np.min(gray)
    
    # ??S?????
    slope = (max_val - min_val) / (power + 1)
    scale = (max_val - min_val) / (max_val - min_val)
    
    # ??S?????
    gray = gray * slope + min_val
    
    # ???????
    gray = (gray * contrast) / 255
    
    # ????0-255???
    gray = np.clip(gray, 0, 255).astype(img.dtype)
    return gray

????????????????????????????????power????????????????contrast????????????