生成PDF 
使用Python的ReportLab库将处理后的位图生成PDF文件。 
 
以下是一个完整的Python示例代码,演示如何实现这些步骤: 
 
python 
 
from PIL import Image 
import numpy as np 
from reportlab.pdfgen import canvas 
from reportlab.lib.pagesizes import letter 
 
def create_color_gradient(color, levels=256): 
    """ 
    Create a color gradient for the specified color. 
    :param color: Tuple of RGB values (e.g., (255, 0, 0) for red) 
    :param levels: Number of gradient levels 
    :return: List of gradient colors 
    """ 
    gradient = [] 
    for i in range(levels): 
        r = int(color[0] * (i / (levels - 1))) 
        g = int(color[1] * (i / (levels - 1))) 
        b = int(color[2] * (i / (levels - 1))) 
        gradient.append((r, g, b)) 
    return gradient 
 
def apply_color_gradient(image, gradient): 
    """ 
    Apply the color gradient to the image. 
    :param image: PIL Image object 
    :param gradient: List of gradient colors 
    :return: PIL Image object with applied gradient 
    """ 
    image = image.convert("L")  # Convert to grayscale 
    image_data = np.array(image) 
    color_image_data = np.zeros((image_data.shape[0], image_data.shape[1], 3), dtype=np.uint8) 
 
    for i in range(image_data.shape[0]): 
        for j in range(image_data.shape[1]): 
            color_image_data[i, j] = gradient[image_data[i, j]] 
 
    color_image = Image.fromarray(color_image_data, "RGB") 
    return color_image 
 
def save_image_to_pdf(image, pdf_path): 
    """ 
    Save the image to a PDF file. 
    :param image: PIL Image object 
    :param pdf_path: Path to the output PDF file 
    """ 
    c = canvas.Canvas(pdf_path, pagesize=letter) 
    image_path = "temp_image.png" 
    image.save(image_path) 
    c.drawImage(image_path, 0, 0, width=letter[0], height=letter[1]) 
    c.showPage() 
    c.save() 
 
def main(): 
    # Step 1: Read the original bitmap 
    original_image_path = "path_to_your_bitmap_image.bmp" 
    image = Image.open(original_image_path) 
 
    # Step 2: Create the specified color gradient 
    specified_color = (255, 0, 0)  # Example: red color gradient 
    gradient = create_color_gradient(specified_color) 
 
    # Step 3: Replace original bitmap colors with the color gradient 
    color_image = apply_color_gradient(image, gradient) 
 
    # Step 4: Save the result to a PDF 
    output_pdf_path = "output_image.pdf" 
    save_image_to_pdf(color_image, output_pdf_path) 
    print(f"PDF saved to {output_pdf_path}") 
 
if __name__ == "__main__": 
    main() 
 
 
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