如何半色调黑白照片？

本文介绍了如何半色调黑白照片？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 我想将图片划分为相同的大正方形，并测量平均灰度等级并将其替换为blob，即半色调。这段代码给了我一张照片，但看起来并不正确。什么想法可能是错的？ im = scipy.misc.imread（uggla.tif） def halftoning（im ）： im = im.astype（'float64'） width，height = im.shape halftone_pic = np.zeros（（width，height）） for x in范围（宽度）：范围内的y（高度）： floating_matrix = im [x：x + 1，y：y + 1] sum = np.sum（floating_matrix） mean = np.mean（sum） round =（mean> 128）* 255 halftone_pic [x，y] = round fig，ax = plt.subplots（1 ，2） ax [0] .imshow（im，cmap =gray） ax [1] .imshow（halftone_pic，cmap =gray） plt.show（） 解决方案这里有一些代码可以满足您的需求。我从一个答案中修改了一些代码到某个 生成半色调结果： I want to divide a picture in equally big squares and measure the average gray scale level and replace it with a blob, aka halftoning. This code gives me a picture but it doesn't look right. Any ideas what could be wrong? im = scipy.misc.imread("uggla.tif")def halftoning(im): im = im.astype('float64') width,height = im.shape halftone_pic = np.zeros((width, height)) for x in range(width): for y in range(height): floating_matrix = im[x:x + 1, y:y + 1] sum = np.sum(floating_matrix) mean = np.mean(sum) round = (mean > 128) * 255 halftone_pic[x,y] = round fig, ax = plt.subplots(1,2) ax[0].imshow(im, cmap="gray") ax[1].imshow(halftone_pic, cmap="gray") plt.show() 解决方案 Here's some code that does what you want. I adapted some code from one answer to a somewhat related question:from PIL import Image, ImageDraw, ImageStat# Adaption of answer https://stackoverflow.com/a/10575940/355230def halftone(img, sample, scale, angle=45): ''' Returns a halftone image created from the given input image "img". "sample" (in pixels), determines the sample box size from the original image. The maximum output dot diameter is given by "sample" * "scale" (which is also the number of possible dot sizes). So "sample" == 1 will preserve the original image resolution, but "scale" must be > 1 to allow variations in dot size. ''' img_grey = img.convert('L') # Convert to greyscale. channel = img_grey.split()[0] # Get grey pixels. channel = channel.rotate(angle, expand=1) size = channel.size[0]*scale, channel.size[1]*scale bitmap = Image.new('1', size) draw = ImageDraw.Draw(bitmap) for x in range(0, channel.size[0], sample): for y in range(0, channel.size[1], sample): box = channel.crop((x, y, x+sample, y+sample)) mean = ImageStat.Stat(box).mean[0] diameter = (mean/255) ** 0.5 edge = 0.5 * (1-diameter) x_pos, y_pos = (x+edge) * scale, (y+edge) * scale box_edge = sample * diameter * scale draw.ellipse((x_pos, y_pos, x_pos+box_edge, y_pos+box_edge), fill=255) bitmap = bitmap.rotate(-angle, expand=1) width_half, height_half = bitmap.size xx = (width_half - img.size[0]*scale) / 2 yy = (height_half - img.size[1]*scale) / 2 bitmap = bitmap.crop((xx, yy, xx + img.size[0]*scale, yy + img.size[1]*scale)) return Image.merge('1', [bitmap])# Sample usageimg = Image.open('uggla.tif')img_ht = halftone(img, 8, 1)img_ht.show()Here's the results from using this as the input image:Halftoned result produced: 这篇关于如何半色调黑白照片？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！