Baseline Widely available
CanvasRenderingContext2D.getImageData()
- меÑод Canvas 2D API, возвÑаÑÐ°ÐµÑ Ð¾Ð±ÑÐµÐºÑ ImageData
, пÑедÑÑавлÑÑÑий базовÑе пикÑелÑнÑе даннÑе Ð´Ð»Ñ Ð¾Ð±Ð»Ð°ÑÑи Ñ
олÑÑа, обознаÑенного пÑÑмоÑголÑником, коÑоÑÑй наÑинаеÑÑÑ Ð² ÑоÑке (sx, sy) и Ð¸Ð¼ÐµÐµÑ ÑиÑÐ¸Ð½Ñ sw и вÑÑоÑÑ sh.
ImageData ctx.getImageData(sx, sy, sw, sh);ÐаÑамеÑÑÑ
sx
ÐооÑдинаÑа x веÑÑ Ð½ÐµÐ³Ð¾ левого Ñгла пÑÑмоÑголÑника, из коÑоÑого бÑÐ´ÐµÑ Ð¸Ð·Ð²Ð»ÐµÑÑн ImageData.
sy
ÐооÑдинаÑа y веÑÑ Ð½ÐµÐ³Ð¾ левого Ñгла пÑÑмоÑголÑника, из коÑоÑого бÑÐ´ÐµÑ Ð¸Ð·Ð²Ð»ÐµÑÑн ImageData.
sw
ШиÑина пÑÑмоÑголÑника, из коÑоÑого бÑÐ´ÐµÑ Ð¸Ð·Ð²Ð»ÐµÑÑн ImageData.
sh
ÐÑÑоÑа пÑÑмоÑголÑника, из коÑоÑого бÑÐ´ÐµÑ Ð¸Ð·Ð²Ð»ÐµÑÑн ImageData.
ÐбÑÐµÐºÑ ImageData
, ÑодеÑжаÑий даннÑе изобÑÐ°Ð¶ÐµÐ½Ð¸Ñ Ð´Ð»Ñ Ð´Ð°Ð½Ð½Ð¾Ð³Ð¾ пÑÑмоÑголÑника Ñ
олÑÑа.
IndexSizeError
ÐÑбÑаÑÑваеÑ, еÑли аÑгÑÐ¼ÐµÐ½Ñ Ð²ÑÑоÑÑ Ð¸Ð»Ð¸ ÑиÑÐ¸Ð½Ñ Ñавен нÑлÑ.
SecurityError
The canvas contains or may contain pixels which were loaded from an origin other than the one from which the document itself was loaded. To avoid SecurityError
being thrown in this situation, configure CORS to allow the source image to be used in this way. See Allowing cross-origin use of images and canvas.
This example draws a rectangle, and then uses getImageData()
to grab a portion of the canvas.
<canvas id="canvas"></canvas>
JavaScript
The object retrieved by getImageData()
has a width of 200 and a height of 100, for a total of 20,000 pixels. Of those pixels, most are either transparent or taken from off the canvas; only 5,000 of them are opaque black (the color of the drawn rectangle).
const canvas = document.getElementById("canvas");
const ctx = canvas.getContext("2d");
ctx.rect(10, 10, 100, 100);
ctx.fill();
let imageData = ctx.getImageData(60, 60, 200, 100);
ctx.putImageData(imageData, 150, 10);
Result СпеÑиÑикаÑии СовмеÑÑимоÑÑÑ Ñ Ð±ÑаÑзеÑами СмоÑÑиÑе Ñакже
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