What is Image and Video Resolution?

Image and Video Resolution: Simple Definition

Resolution refers to the number of pixels (individual colored dots) that make up an image or video frame. A 1920x1080 resolution means 1920 pixels wide by 1080 pixels tall, totaling about 2 million pixels.

Higher resolution means more detail, but also larger file sizes. A 4K image (3840x2160) has 4 times more pixels than a 1080p image, so it requires roughly 4 times more storage.

Pixel Count and Aspect Ratio

Resolution states the horizontal and vertical pixel counts, and their ratio fixes the image's shape—1920×1080 and 1280×720 both describe the 16:9 widescreen aspect ratio.^[2] Because total pixels grow with the product of width and height, doubling each dimension quadruples the pixel count and the raw data required.^[1]

Resolution versus Pixel Density

Resolution alone does not determine sharpness as perceived by a viewer. Pixel density, measured in pixels per inch (PPI), depends on how many pixels are packed into the physical screen or print size.^[3] The same 1080p image looks crisp on a phone but coarse when stretched across a large wall display, since the pixels are spread over more area.^[3]

Why Higher Is Not Always Better

Beyond the resolving limit of the human eye at a given viewing distance, extra pixels add file size and processing load without visible benefit.^[3] Upscaling a low-resolution image to a larger pixel grid cannot recover detail that was never captured; it only interpolates new pixels from existing ones.^[1]

Understanding Resolution

Resolution is often measured in total pixels (megapixels) for cameras, or by the height in lines for video. A 12-megapixel camera captures 12 million pixels per photo. “1080p” video has 1080 horizontal lines of pixels.

Screen resolution determines how sharp your display looks. A 4K monitor shows more pixels per inch than a 1080p monitor of the same size, resulting in sharper, more detailed images.

Examples of Image and Video Resolution

Frequently Asked Questions