Skip to content

Commit

Permalink
fixed typo
Browse files Browse the repository at this point in the history
  • Loading branch information
genekogan committed Dec 27, 2018
1 parent 3208d42 commit e97198f
Showing 1 changed file with 1 addition and 1 deletion.
2 changes: 1 addition & 1 deletion _chapters/convnets.md
Expand Up @@ -150,7 +150,7 @@ Let's zoom out from what we just looked at and see the bigger picture. From this

In this sense, we can think of the original image as a volume of data. Let's consider the previous example. Our original image is 28 x 28 pixels and is grayscale (1 channel). Thus it is a volume whose dimensions are 28x28x1. In the first convolutional layer, we convolved it with 8 filters whose dimensions are 5x5x1. This gave us 8 activation maps of size 24x24. Thus the output from the convolutional layer is size 24x24x8. After max-pooling it, it's 12x12x8.

What happens if the original image is color? In this case, our analogy scales very simply. Our convolutional filters would then also be color, and therefore have 3 channels. The convolution operation would work exactly as it did before, but simply have three times as many multiplications to make; the multiplications continue to line up by x and y as before, but also now by channel. So suppose we were using CIFAR-10 color images, whose size is 32x32x5, and we put it through a convolutional layer consisting of 20 filters of size 7x7x3. Then the output would be a volume of 26x26x20. The size in the x and y dimensions is 26 because there are 26x26 possible positions to slide a 7x7 filter into inside of a 32x32 image, and its depth is 20 because there are 20 filters.
What happens if the original image is color? In this case, our analogy scales very simply. Our convolutional filters would then also be color, and therefore have 3 channels. The convolution operation would work exactly as it did before, but simply have three times as many multiplications to make; the multiplications continue to line up by x and y as before, but also now by channel. So suppose we were using CIFAR-10 color images, whose size is 32x32x3, and we put it through a convolutional layer consisting of 20 filters of size 7x7x3. Then the output would be a volume of 26x26x20. The size in the x and y dimensions is 26 because there are 26x26 possible positions to slide a 7x7 filter into inside of a 32x32 image, and its depth is 20 because there are 20 filters.

{% include figure_multi.md path1="/images/figures/cnn_volumes.jpg" caption1="Volumes (source: <a href=\"https://cs231n.github.io/convolutional-networks/\">CS231n</a>)" %}

Expand Down

0 comments on commit e97198f

Please sign in to comment.