4.9. Performance

Performance can be an important consideration when you are manipulating images. This section discusses three benchmarks from jsperf.com that address the following performance concerns:

• Looping through image data

• Using drawImage() vs. putImageData()

• Drawing a canvas instead of an image with drawImage()

• Scaling when you draw images with drawImage()

As always, be aware that the results of any benchmark can change significantly over time and across different browsers. You should regard all the performance recommendations that follow as guidelines for your own code, not as fundamental principles. It’s also a good idea to go to jsperf.com to look the current state of the benchmarks.

4.9.1. drawImage(HTMLImage) vs. drawImage(HTMLCanvas) ...

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