PHP can create images of different sizes. It depends on a particular image.
The change in size of an image compared with the size of an object is termed magnification. This can be calculated as the ratio of the size of the image to the size of the object. Magnification can be expressed as magnification = image size / object size.
image-Image Size
No, the size of the image does not increase as the image distance increases. The size of the image is determined by the object distance, focal length of the lens, and the distance between the lens and the image plane.
To calculate the pixel size of an image, you need to divide the width or height of the image in pixels by the physical size of the image in inches. This will give you the pixel size per inch.
One way to measure the size of an object from an image is to use a known reference object of a standard size in the same image. By comparing the size of the reference object to the size of the object you want to measure, you can calculate the size of the object in the image.
In Photoshop go to Image > Image Size.
That depend on resolution. Open image in Photoshop and go to Image > Image Size. Pixel dimensions you can see on the top of Image Size window.
What size print will an image that is 7.8 MP?
The size of the image is a scaled representation of the original object, typically smaller or larger. The relationship between the size of the image and the size of the original object is determined by the magnification factor of the optical system used to capture the image.
You can enlarge image in Image Size dialog in Photoshop, Image > Image Size. At top of window you will see current/new size in bytes. When you enlarging images be aware because you can loose quality.
Go to Image > Image Size and type numbers or choose Percentage and type percentage in Height or Width fields at top of Image Size window.
compression ratio=uncompressed image size/compressed size