Is an image pyramid (either Laplacian or Gaussian) used in a specific image file format type, or is it just the standard way to store any image? And do programs that open the images (powerpoint, etc) just access the file at different sizes when they're resized, or do they still have to downsample manually if the image size isn't included in the pyramid?
mpotoole
No, it's not usually saved in an image file format (it'd make the images x4/3 larger to store!). Typically you would need to compute the image pyramid yourself. So for any program that wants to resize images (e.g., PowerPoint, Photoshop), they need to either (i) resample images on demand, or (ii) precompute a Gaussian image pyramid and sample when needed. The latter is also used in computer graphics to prevent aliasing, in which case is often referred to as a mipmap.
Is an image pyramid (either Laplacian or Gaussian) used in a specific image file format type, or is it just the standard way to store any image? And do programs that open the images (powerpoint, etc) just access the file at different sizes when they're resized, or do they still have to downsample manually if the image size isn't included in the pyramid?
No, it's not usually saved in an image file format (it'd make the images x4/3 larger to store!). Typically you would need to compute the image pyramid yourself. So for any program that wants to resize images (e.g., PowerPoint, Photoshop), they need to either (i) resample images on demand, or (ii) precompute a Gaussian image pyramid and sample when needed. The latter is also used in computer graphics to prevent aliasing, in which case is often referred to as a mipmap.