PPI is defined as what?

• A. The number of colors per inch
• B. The size of the image in pixels
• C. The frame rate of the video
• D. The number of pixels per linear inch in an image

Answer: (D)

PPI measures how densely pixels are packed in an image along a single dimension. It tells you how many pixels appear in each inch when the image is displayed or printed. This density controls sharpness: at a fixed print size, increasing PPI adds more samples and makes edges crisper; at a fixed pixel size, increasing PPI would require a smaller printed size.

For example, a 3000-by-2400-pixel image printed at 300 PPI would yield dimensions of 10 inches by 8 inches (3000/300 by 2400/300). If you printed the same image at 150 PPI, it would be 20 by 16 inches but with noticeably less sharpness.

PPI is not about the number of colors per inch, nor about frame rate. It’s specifically the number of pixels per linear inch in an image.