Существует ли стандартный размер бумаги формата А4 в пикселях?
Размеры бумаги формата А4 составляют 210 мм × 297 мм или 8,27 дюйма × 11,69 дюйма.
Для разрешения 600 точек на дюйм я рассчитываю размер бумаги в пикселях, как показано ниже:
В имперской системе:
Horizontal size = (8.27in) x (600 pixels/in) = 4962 pixels Vertical size = (11.69in) x (600 pixels/in) = 7014 pixels В метрической системе:
Horizontal = ((210mm) / (25.4mm/in)) x (600 pixels/in) = 4960.6299 pixels ≅ 4961 pixels Vertical = ((297mm) / (25.4mm/in)) x (600 pixels/in) = 7015.7480 pixels ≅ 7016 pixels В этом ответе и на этом форуме это называется 4960 x 7016 pixels.
Почему эти цифры не держатся? Каковы истинные размеры бумаги формата А4 в пикселях в разных разрешениях?
A4 is precisely 210mm x 297mm. Your calculation in the metric system is correct. The 1 pixel difference is likely due to improper rounding, and anyhow it's less than 0.02% of the width.
A more precise determination of the A4 size in inches is: 8.2677 in x 11.6929, which would make the numbers match.
There is no "standard" size as it depends on the resolution you wish to print at, so your calculations are correct.
Any discrepancy is due to rounding in the calculations where those performing the calculations rounded the intermediate values rather than waiting until the end (as you have done).
A one or two pixel difference across 5,000 pixels isn't going to be noticeable.
The most important thing to note is that 210 / 25.4 is only approximately 8.27. To more decimal places it's 8.2677165 - how many decimal places you take in this calculation will determine how accurate your result is.
At 300 dpi you will get:
Horizontal size = (8.27in) x (300 pixels/in) = 2481 Vertical size = (11.69in) x (300 pixels/in) = 3507 Horizontal size = ((210mm) / (25.4mm/in)) x (300 pixels/in) = 2480.3150 ≅ 2481 Vertical size = ((297mm) / (25.4mm/in)) x (300 pixels/in) = 3507.8740 ≅ 3508 Which you can see also vary slightly with the calculations you use.