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The Metric Pixel Canvas is a pixel based derivative of the ISO 216 standard developed by Dennis Pennekamp to unite pixel based raster graphics with vector graphics on a square root of two based metric canvas. From the list we can derive the following: * The base unit is a square pixel of 0.25 x 0.25 mm. (Which establishes a resolution of approximately 102 dpi.) * The line thickness is 0.25 mm by default. (Which is nice as one can buy 0.25 mm pens in a shop.) * The dA4 size qualifies as an A4 paper size according to the margins allowed by ISO 216. (Which means you can simply print to A4 even if the A4 was cut on the small side, and if you don't care about minimal distortion you can print it resized to fit to your A4 paper exactly) * Like ISO 216 it uses a 1:√2 aspect ratio by approximation. (Which means that a large canvas can be cut in two to create 2 pieces of almost exactly the same aspect ratio, without adding any margins or creating any loss) * Unlike ISO 216 it does not repeatedly round to the nearest millimetre or allow for increasing margins. (Which means no pixels are ever lost during two step scaling, while one step scaling creates an approximation error which is always the same percentage and can therefore be nullified when repeated.) ==Scaling== For example, to project dA4 onto dA3, multiply the sides in accordance with the aspect ratio: 819 x (52 / 37) = 1664 589 x (37 / 26) = 1184 This creates non square pixels, although to the untrained eye indistinguishable from 0.35 mm squares which means one can again use a standard (0.35 mm) pen to continue drawing the former 0.25 mm lines on a print out. When repeated the fractions are exchanged to nullify the error: 1664 x (37 / 26) = 2368 1184 x (52 / 37) = 1664 The resulting dA2 is exactly twice the size of dA4 with 0.5 mm square pixels. Vice versa, when projecting dA2 onto dA4, we have simply doubled the printing resolution. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Metric Pixel Canvas」の詳細全文を読む スポンサード リンク
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