Run results for: drawImage() scaling down performance

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 13_3_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.0.5 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 13

Operating system: iOS 13.3.1

Device Platform: Mobile

Date tested: 4 years ago

Test name	Executions per second
Scaling from a large canvas area to a small canvas area	348.7 Ops/sec
Scaling from a large canvas area to a medium canvas area	204.1 Ops/sec
Scaling from a large canvas area to a large canvas area (no scaling)	86.6 Ops/sec

Script Preparation code:

$sourceWidth = 3000;
$sourceHeight = 3000;
$sourceCanvas = document.createElement("canvas");
$sourceCanvas.width = $sourceWidth;
$sourceCanvas.height = $sourceHeight;
$sourceContext = $sourceCanvas.getContext("2d");
$sourceContext.fillStyle = "rgba(0,100,200,1)";
$sourceContext.fillRect(0, 0, $sourceWidth, $sourceHeight);

$destCanvas = document.createElement("canvas");
$destCanvas.width = $sourceWidth;
$destCanvas.height = $sourceHeight;
$destContext = $destCanvas.getContext("2d");

Tests:

Scaling from a large canvas area to a small canvas area
$destContext.drawImage($sourceCanvas, 0, 0, $sourceWidth, $sourceHeight, 0, 0, 100, 100); // Force the drawImage call to be evaluated within this benchmark code: $destContext.getImageData(0, 0, 1, 1);
Scaling from a large canvas area to a medium canvas area
$destContext.drawImage($sourceCanvas, 0, 0, $sourceWidth, $sourceHeight, 0, 0, 600, 600); // Force the drawImage call to be evaluated within this benchmark code: $destContext.getImageData(0, 0, 1, 1);
Scaling from a large canvas area to a large canvas area (no scaling)
$destContext.drawImage($sourceCanvas, 0, 0, $sourceWidth, $sourceHeight, 0, 0, $sourceWidth, $sourceHeight); // Force the drawImage call to be evaluated within this benchmark code: $destContext.getImageData(0, 0, 1, 1);

Run results for: drawImage() scaling down performance

Scaling from a large canvas area to a small canvas area

Scaling from a large canvas area to a medium canvas area

Scaling from a large canvas area to a large canvas area (no scaling)