Learn: Calculating Image File Size (Colour Depth × Width × Height)

Welcome!You've already explored topics like data units and binary storage. Today, we'll learn how to calculate the size of image files using their colour depth, width, and height.

Why Calculate Image File Size?Knowing how to calculate image file size helps us understand storage requirements for images. This is important when choosing devices or storage media that can handle specific file sizes.

Key TermsColour depth refers to the number of bits used per pixel to represent colours in an image. Width and height are the dimensions of the image, measured in pixels.

Formula for Image File SizeThe file size of an image can be calculated using the formula: File size = Colour depth × Width × Height. The result will be in bits. To convert to bytes, divide by 8.

Step-by-Step ExampleImagine an image with a colour depth of 8 bits, 200 pixels wide, and 100 pixels high. Using the formula: 8 × 200 × 100 = 160,000 bits. Converting to bytes: 160,000 ÷ 8 = 20,000 bytes.

Converting Bits to BytesAfter calculating the file size in bits, divide the result by 8 to convert it to bytes. This step is important because storage devices measure file sizes in bytes, not bits.

Review Time!Great work! We've covered how to calculate image file size using colour depth, width, and height. Now let's test your understanding with a few questions.