Photo/Image/Pictur Calculation Pixel DPI for printing and editing
| Units | |
|---|---|
| engl. measure | 1 Inch = 25.4 mm |
| Dot per Inch | 1 dpi = 1 Dot per Inch(25.4 mm) |
| pixels per Inch | 1 ppi = 1 dpi = 1 Pixel per Inch(25.4 mm) |
| Digital |
B = Byte 1 bit = 0 | 1 1 B = 8 bit 1 kB = 1024 B 1 MB = 1024 kB |
| Example : pixels/Bytes calculate - image: 1000px · 2000px | |
|---|---|
\(Bytes = {Total pixels × color depth \over 8 Bit [1 Byte]}\) |
\({(1000px · 2000px) × 24 \over 8 bit × 1M} = 6MB\) |
| Example: Photo/Image/Pictur 5x5 pixels (12.7 x 12.7 mm) Formula calculation of length or width, pixels and dpi |
|
|---|---|
\(length [mm] = {Pixel × 1 Inch [25.4mm] \over dpi}\) |
\({5px × 25.4mm \over 10 dpi} = 12.7 mm\) |
\(Pixel = {dpi × length [mm] \over 1 Inch [25.4mm]}\) |
\({10dpi × 12.7mm \over 25.4mm} = 5px\) |
\(dpi = {Pixel × 1 Inch [25.4mm] \over length [mm]}\) |
\({5px × 25.4mm \over 12.7mm} = 10dpi\) |
| Image for print 300 dpi, for photo album - Photo/Image/Pictur: 13 x 18 cm Quality of print 300 dpi - Resolution in pixels? |
|
|---|---|
Vertical 13cm [130mm] |
\({300dpi × 130mm \over 25.4mm} = 1535 Pixel\) |
Horizontally 18cm [180mm] |
\({300dpi × 180mm \over 25.4mm} = 2126 Pixel\) |
Total pixels [Mpx] |
\({1535px × 2126px \over 1'000'000} = = 3.26 MegaPixel\) |
| Print Image 300 dpi, for photo album - Image: 1024 x 768 pixels Quality of print: 300 dpi - Which picture size for printing? |
|
|---|---|
Vertical 768 Pixel |
\({768px × 25.4mm \over 300 dpi} = 65 mm\) |
Horizontally 1024 Pixel |
\({1024px × 25.4mm \over 300 dpi} = 87 mm\) |
| slide scanning for a slideshow on the TV - TV 40 inch Resolution : 1'920 x 1'080 pixels Photo-Slide : 24 x 36 mm - Scan resolution? |
|
|---|---|
Vertical 1'080 pixels 1080 Pixel |
\({1080px × 25.4mm \over 24 mm} = 1143 dpi\) |
| Image Size Horizontally: | |
Horizontally 18cm [180mm] |
\({1143 dpi × 36 mm \over 25.4 mm} = 1620 Pixel\) |
| Slide scanning for print a Poster - Slide Size : 24 x 36 mm Poster Size : 900 x 600 mm Scanner Resolution: 4000 dpi DPI 1:1 - Scan resolution? |
|
|---|---|
| 1. Pixels: | |
Horizontally 36 mm |
\({4000 dpi × 36 mm \over 25.4 mm} = 5669 Pixel\) |
| 2. Poster | |
Slide horizontally 36mm |
\({5669 px × 25.4 mm \over 900 mm} = 160 dpi\) |
