Improve image normalising
parent
ae5128a33a
commit
d0e428b728
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@ -23,11 +23,17 @@ class ParseQRCode extends Operation {
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this.name = "Parse QR Code";
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this.module = "Image";
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this.description = "Reads an image file and attempts to detect and read a QR code from the image.";
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this.description = "Reads an image file and attempts to detect and read a QR code from the image.<br><br><u>Normalise Image</u><br>Attempt to normalise the image before parsing it, to try and improve detection of a QR code.";
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this.infoURL = "https://wikipedia.org/wiki/QR_code";
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this.inputType = "byteArray";
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this.outputType = "string";
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this.args = [];
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this.args = [
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{
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"name": "Normalise image",
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"type": "boolean",
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"value": true
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}
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];
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}
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/**
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@ -37,38 +43,55 @@ class ParseQRCode extends Operation {
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*/
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async run(input, args) {
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const type = Magic.magicFileType(input);
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const [normalise] = args;
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// Make sure that the input is an image
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if (type && type.mime.indexOf("image") === 0){
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return new Promise((resolve, reject) => {
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// Read the input
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let normalisedImage = null;
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if (normalise){
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// Process the image to be easier to read by jsqr
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// Disables the alpha channel
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// Sets the image default background to white
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// Normalises the image colours
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// Makes the image greyscale
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// Converts image to a JPEG
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normalisedImage = await new Promise((resolve, reject) => {
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jimp.read(Buffer.from(input))
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.then(image => {
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image.rgba(false); // Disable RGBA (uses just RGB)
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// Get the buffer of the new image and read it in Jimp
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// Don't actually need the new image buffer, just need
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// Jimp to refresh the current object
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image.getBuffer(image.getMIME(), (err, buffer) => {
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jimp.read(buffer)
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.then(newImage =>{
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// If the image has been read correctly, try to find a QR code
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image
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.rgba(false)
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.background(0xFFFFFFFF)
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.normalize()
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.greyscale()
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.getBuffer(jimp.MIME_JPEG, (error, result) => {
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resolve([...result]);
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});
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})
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.catch(err => {
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reject(new OperationError("Error reading the image file."));
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});
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});
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} else {
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normalisedImage = input;
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}
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if (normalisedImage instanceof OperationError){
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return normalisedImage;
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}
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return new Promise((resolve, reject) => {
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jimp.read(Buffer.from(normalisedImage))
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.then(image => {
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if (image.bitmap != null){
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const qrData = jsqr(image.bitmap.data, image.getWidth(), image.getHeight());
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if (qrData != null){
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resolve(qrData.data);
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} else {
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log.error(image.bitmap);
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reject(new OperationError("Error parsing QR code from image."));
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reject(new OperationError("Couldn't read a QR code from the image."));
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}
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} else {
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reject(new OperationError("Error reading the image data."));
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reject(new OperationError("Error reading the normalised image file."));
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}
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});
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});
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})
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.catch(err => {
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reject(new OperationError("Error opening the image. Are you sure this is an image file?"));
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reject(new OperationError("Error reading the normalised image file."));
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});
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});
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} else {
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