Using a Web Worker to get Image Data (width, height and pixel data), cross browser
I'm creating a web worker to fetch an image, and then return some metadata (width, height, and the average darkness of the image, calculated from image pixel data).
So far I have a worker which works to get the image width and height, however it only works in Chrome, as it relies on createImageBitmap(). I am also unable as far as I can see to access pixel data values.
self.onmessage = (e) => {
const { url, key } = e.data;
fetch(url, {
method: 'GET',
mode: 'cors',
cache: 'default'
}).then(response => {
return response.blob();
}).then(async (blob) => {
const image = await self.createImageBitmap(blob);
self.postMessage({ url, key, metadata: {
width: image.width,
height: image.height,
aspectRatio: image.width / image.height,
}});
image.close();
});
}
Is there a way which this can be achieved without passing the image back to the main thread to get the image data.
javascript multithreading image web-worker imagedata
asked Nov 24 '18 at 14:53
Jack WildJack Wild
70111324
add a comment |
I'm creating a web worker to fetch an image, and then return some metadata (width, height, and the average darkness of the image, calculated from image pixel data).
So far I have a worker which works to get the image width and height, however it only works in Chrome, as it relies on createImageBitmap(). I am also unable as far as I can see to access pixel data values.
self.onmessage = (e) => {
const { url, key } = e.data;
fetch(url, {
method: 'GET',
mode: 'cors',
cache: 'default'
}).then(response => {
return response.blob();
}).then(async (blob) => {
const image = await self.createImageBitmap(blob);
self.postMessage({ url, key, metadata: {
width: image.width,
height: image.height,
aspectRatio: image.width / image.height,
}});
image.close();
});
}
Is there a way which this can be achieved without passing the image back to the main thread to get the image data.
javascript multithreading image web-worker imagedata
asked Nov 24 '18 at 14:53
Jack WildJack Wild
70111324
add a comment |
I'm creating a web worker to fetch an image, and then return some metadata (width, height, and the average darkness of the image, calculated from image pixel data).
So far I have a worker which works to get the image width and height, however it only works in Chrome, as it relies on createImageBitmap(). I am also unable as far as I can see to access pixel data values.
self.onmessage = (e) => {
const { url, key } = e.data;
fetch(url, {
method: 'GET',
mode: 'cors',
cache: 'default'
}).then(response => {
return response.blob();
}).then(async (blob) => {
const image = await self.createImageBitmap(blob);
self.postMessage({ url, key, metadata: {
width: image.width,
height: image.height,
aspectRatio: image.width / image.height,
}});
image.close();
});
}
Is there a way which this can be achieved without passing the image back to the main thread to get the image data.
javascript multithreading image web-worker imagedata
asked Nov 24 '18 at 14:53
Jack WildJack Wild
70111324
I'm creating a web worker to fetch an image, and then return some metadata (width, height, and the average darkness of the image, calculated from image pixel data).
So far I have a worker which works to get the image width and height, however it only works in Chrome, as it relies on createImageBitmap(). I am also unable as far as I can see to access pixel data values.
self.onmessage = (e) => {
const { url, key } = e.data;
fetch(url, {
method: 'GET',
mode: 'cors',
cache: 'default'
}).then(response => {
return response.blob();
}).then(async (blob) => {
const image = await self.createImageBitmap(blob);
self.postMessage({ url, key, metadata: {
width: image.width,
height: image.height,
aspectRatio: image.width / image.height,
}});
image.close();
});
}
Is there a way which this can be achieved without passing the image back to the main thread to get the image data.
javascript multithreading image web-worker imagedata
javascript multithreading image web-worker imagedata
asked Nov 24 '18 at 14:53
Jack WildJack Wild
70111324
asked Nov 24 '18 at 14:53
Jack WildJack Wild
70111324
asked Nov 24 '18 at 14:53
Jack WildJack Wild
70111324
asked Nov 24 '18 at 14:53
Jack WildJack Wild
70111324
asked Nov 24 '18 at 14:53
Jack WildJack Wild
70111324
70111324
add a comment |
add a comment |
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