Subsampling vs downsampling

1. Is subsampling the same as downsampling?
2. What is the difference between sampling and subsampling?
3. What is subsampling in image processing?
4. What is the difference between upsampling and downsampling?

Is subsampling the same as downsampling?

Pooling in the convolutional network is termed as downsampling or subsampling, which minimizes the number of neurons in the convolutional layer by retaining the important information.

What is the difference between sampling and subsampling?

A sample is a portion of the population. A subsample is a portion of the sample.

What is subsampling in image processing?

Subsampling reduces the image size by removing information all together. Usually when you subsample, you also interpolate or smooth the image so that you reduce aliasing. Sub-sampling has another application in video processing - especially in MPEG where video is encoded in YCbCr.

What is the difference between upsampling and downsampling?

Downsampling is the reduction in spatial resolution while keeping the same two-dimensional (2D) representa- tion. It is typically used to reduce the storage and/or transmission requirements of images. Upsampling is the increasing of the spatial resolution while keeping the 2D representation of an image.