Image Resizing and Resampling

Tommy Sarginson

Image Resizing and Resampling

Load an image of your choice, then go to the ‘Image’ menu at the top then click on ‘Image Size’.

Next a window will pop up showing the image size settings. You can change the Width, Height and Resolution, it also shows the image size in megabytes. When you change one of the values they all change to fit to the original size. Therefore, the number of pixels increase when the dimensions of image decrease so that the same number of pixels fit in the same area. This means that in a smaller image there is a higher resolution. This is ok if you are working on the image on a computer because you can work the pixels on a screen however if the image needs to be printed the printer cannot print that higher quality. To change the resolution with changing the dimensions of the image you can select the ‘Resample’ option. This means that the size of image can be changed but it keep the same resolution.

Resolution

Resolution is the number of pixels in a certain area, usually per inch. Each pixel is a colour so many of them create a coloured image. The more pixels in an image increase the resolution creating a higher quality image.

Up and Down Sampling
Up sampling is when the image size is increased there are less pixels so the software add more
pixels to increase the resolution. It works out the colours at each side then creates a similar 
coloured pixel.