Does resampling affect the image quality?
When you turn on Resample, you can change any of the values in the Image Size dialog: pixel dimensions, physical size, or resolution. Changing the pixel dimensions affects the physical size but not the resolution. Changing the resolution affects the pixel dimensions but not the physical size.
What is the purpose of resampling an image?
Resample. Changing the pixel dimensions of an image is called resampling. Resampling can degrade image quality. Downsampling decreases the number of pixels in the image, while upsampling increases the number.
When to use resampling to reduce image resolution?
Reduce Resolution Suppose that instead of resampling during reprojection, your goal is to aggregate pixels to larger pixels in a different projection. This is useful when comparing image datasets at different scales, for example 30-meter pixels from a Landsat-based product to coarse pixels (higher scale) from a MODIS-based product.
How to change the resolution of an image in Photoshop?
In Photoshop if I use the ‘Resize Image’ option and uncheck ‘Resample Image’ and then change the resolution to 72 obviously the pixel size will stay the same (but the physical dimensions in cm/inches will change).
When to use resampling instead of reprojection?
Suppose that instead of resampling during reprojection, your goal is to aggregate pixels to larger pixels in a different projection. This is useful when comparing image datasets at different scales, for example 30-meter pixels from a Landsat-based product to coarse pixels (higher scale) from a MODIS-based product.
What happens to the resolution of an image when you double the size?
If you double the size of an image, the resolution decreases by half, because the pixels are twice as far apart to fit the physical size. For example, a 400 x 400-pixel image, has a physical size of 4 x 4 inches and has a resolution of 100 pixels per inch (ppi).