Final answer:
Digital photographs are defined by pixel dimensions and bits per pixel, and are influenced by resolution and compression. They can be saved in formats like JPEG, which provides efficient image compression. Image size is measured in megapixels, calculated by multiplying pixel width by height divided by one million.
Step-by-step explanation:
Items characterized by pixel width and height and the number of bits per pixel, which are used to depict digital photographs, can be stored in various file formats and are suitable for display on monitors, projection on screens, or printing on paper. Digital photographs are primarily defined by two factors that influence file size and quality: resolution and compression.
Resolution refers to the number of pixels used to compose a photo. A higher resolution translates to greater detail, allowing images to appear clearer, especially when printed. However, higher resolution images also lead to larger file sizes. Compression is a method used to reduce file size by simplifying the data in an image, potentially at the cost of image quality if overused. JPEG, which stands for Joint Photographic Experts Group, is a popular image format because it provides a good balance of image quality and file size due to its ability to compress images efficiently without a noticeable loss of quality in most cases.
To calculate the size of a photo in megapixels, the pixel width is multiplied by the pixel height and the result is divided by one million. For instance, a 5 MP (megapixel) image would have a resolution of 2560 x 1920 pixels. Most cameras allow users to adjust the resolution and compression to suit their needs, whether for high-quality prints or for images that are optimized for web use with smaller file sizes.