CHART: About digital images

 

Digital image problem 2

 Second problem:

Which resolution would the same picture need to have a 300 dpi picture?

Step 1: Convert millimeters to inches

We know that:

$$1 \text{ inch} = 25.4 \text{ mm}$$

Convert each dimension:

• Width:

  $$210 \div 25.4 = 8.267716535 \text{ inches}$$
  

• Height:

  $$297 \div 25.4 = 11.69291339 \text{ inches}$$
  

Step 2: Multiply each dimension in inches by the desired resolution (300 dpi)

• Width in pixels:

  $$8.267716535 \times 300 = 2480.31496 \text{ px}$$
  

• Height in pixels:

  $$\mathrm{-\; 11.69291339}\times 300=3507.874017\text{ pixels}$$

• Final required resolution: 
• 2480 × 3508 pixels

Digital image problem 1

First problem: 

Think you want to print out a photograph with a size of DIN A4: 210 × 297 mm

maintaining a printing quality of 200 dpi. Which resolution would the image need?

To find the required image resolution:

Step 1: Convert A4 dimensions from millimeters to inches.
1 inch = 25.4 mm

• Width: $210 \div 25.4 \approx 8.27$ in

• Height: $297 \div 25.4 \approx 11.69$ in

Step 2: Multiply by desired print DPI (200 dpi).

• Width: $8.27 \times 200 \approx 1654$ pixels

• Height: $11.69 \times 200 \approx 2338$ pixels

  Required resolution at 200 dpi: 

• 1654 × 2339 pixels