Question

TensorFlow新手在这里训练a simple tutorial我失败了。重点是将图像转换为灰度。

我们的数据基本上是HxWx3（图片的高度，宽度和三个值r，g，b的颜色）。

所以它可能相当于将每个数组单元格从[r, g, b]变换为[gray, gray, gray]，其中gray = mean(r, g, b)对吗？

因此，我检查了文档的平均函数并找到了reduce_mean。我在颜色轴上使用它，即轴= 2，然后再次使用轴2将结果连接到“复制”平均值，最后得到灰色值（=平均值）的3倍，如红色，绿色和蓝色。

请参阅以下代码：

import tensorflow as tf
import matplotlib.image as mpimg

filename = "MarshOrchid.jpg"
raw_image_data = mpimg.imread(filename)

image = tf.placeholder("uint8", [None, None, 3])

# Reduce axis 2 by mean (= color)
# i.e. image = [[[r,g,b], ...]] 
# out = [[[ grayvalue ], ... ]] where grayvalue = mean(r, g, b)
out = tf.reduce_mean(image, 2, keep_dims=True)

# Associate r,g,b to the same mean value = concat mean on axis 2.
# out = [[[ grayvalu, grayvalue, grayvalue], ...]]
out = tf.concat(2, [out, out, out])

with tf.Session() as session:
    result = session.run(out, feed_dict={image: raw_image_data})

print(result.shape)
plt.imshow(result)
plt.show()

(You can get original image here)