Exam Tips - Images & Sound

Exam Tips - Images & Sound

Most common exam questions:

• "Calculate image file size" → Width × Height × Color Depth ÷ 8
• "Calculate sound file size" → Sample Rate × Bit Depth × Duration × Channels ÷ 8
• "What is a pixel?" → Smallest unit of a digital image (picture element)
• "What is sample rate?" → Number of samples per second (Hz)
• "Higher sample rate = ?" → Better quality but larger file

Image calculation tips:

• Always multiply: Width × Height × Color Depth
• Don't forget to divide by 8 to convert bits → bytes
• Watch out for units: KB, MB, or bytes?
• 24-bit color = True Color (most common)

Sound calculation tips:

• Four factors: Sample Rate × Bit Depth × Duration × Channels
• Stereo = ×2 channels (don't forget!)
• Duration must be in seconds
• Divide by 8 for bytes
• CD quality = 44,100 Hz, 16-bit, stereo

Common mistakes to avoid:

• Forgetting to divide by 8 (bits → bytes)
• Missing "× channels" for stereo sound
• Confusing width/height order
• Not converting duration to seconds
• Mixing up sample rate (Hz) with bit depth (bits)