The KB, or kilobyte, size of your photo represents how much space it takes up on your hard drive. It also determines how much data needs to be transferred for it to be sent or downloaded from the Internet. The larger the file, the longer it will take to transfer. Higher KB size images often mean they are higher resolution images, with resolution referring to the quality of the image. The higher the quality, the bigger the file. If you need to reduce or increase the KB size of your images, you'll need to do it using a photo image editing program.
Open your photo file in your photo editing software.
Reduce the size of the image. Generally this can be found in the File or Edit menu. In Adobe Photoshop, for example, you'll find "Image Size" under "Edit."
Save your new file. Generally you find the Save option this under the File menu. In Adobe Photoshop for example, you'd go to "File," then "Save for Web." Here you'll be able to choose from several file formats, each of which encode the image at a different KB size.
Re-scan your image at a higher resolution and file size if you have a physical original.
Open the file in your photo editing software. Choose your desired image size and image resolution. Each software has a different tool for changing image size. In Adobe Photoshop, it's under "Edit," then "Image Size."
Save your new file. Choose the image quality at which you want to save the image. A higher quality image will result in a higher KB size.
Often you can reduce the KB size of the image by reducing the quality of an image without having to decrease the image size at all. Adobe Photoshop is an image editing program often used by graphic designers. GIMP is an open source free alternative. Photoshop Elements is a less expensive version of Photoshop available for non-graphic professionals.
Artificially increasing the file size will not increase its resolution. It will only scale up the lower resolution image. Using a higher resolution image scaled from a lower resolution image can result in an image that looks pixilated and spotty.