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Merge pull request #7210 from Snuffleupagus/extract-PDFImage.resize

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Split the two paths in `PDFImage.resize` into separate helper functions, placed in colorspace.js and image.js
This commit is contained in:
Yury Delendik 2016-04-17 07:49:37 -05:00
commit 3228c9445c
2 changed files with 74 additions and 79 deletions
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49
src/core/colorspace.js
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@ -40,10 +40,42 @@ var isName = corePrimitives.isName;
var isStream = corePrimitives.isStream;
var PDFFunction = coreFunction.PDFFunction;
var coreImage; // see _setCoreImage below
var PDFImage; // = coreImage.PDFImage;
var ColorSpace = (function ColorSpaceClosure() {
/**
* Resizes an RGB image with 3 components.
* @param {TypedArray} src - The source buffer.
* @param {Number} bpc - Number of bits per component.
* @param {Number} w1 - Original width.
* @param {Number} h1 - Original height.
* @param {Number} w2 - New width.
* @param {Number} h2 - New height.
* @param {Number} alpha01 - Size reserved for the alpha channel.
* @param {TypedArray} dest - The destination buffer.
*/
function resizeRgbImage(src, bpc, w1, h1, w2, h2, alpha01, dest) {
var COMPONENTS = 3;
alpha01 = alpha01 !== 1 ? 0 : alpha01;
var xRatio = w1 / w2;
var yRatio = h1 / h2;
var i, j, py, newIndex = 0, oldIndex;
var xScaled = new Uint16Array(w2);
var w1Scanline = w1 * COMPONENTS;
for (i = 0; i < w2; i++) {
xScaled[i] = Math.floor(i * xRatio) * COMPONENTS;
}
for (i = 0; i < h2; i++) {
py = Math.floor(i * yRatio) * w1Scanline;
for (j = 0; j < w2; j++) {
oldIndex = py + xScaled[j];
dest[newIndex++] = src[oldIndex++];
dest[newIndex++] = src[oldIndex++];
dest[newIndex++] = src[oldIndex++];
newIndex += alpha01;
}
}
}
// Constructor should define this.numComps, this.defaultColor, this.name
function ColorSpace() {
error('should not call ColorSpace constructor');
@ -169,8 +201,8 @@ var ColorSpace = (function ColorSpaceClosure() {
if (rgbBuf) {
if (needsResizing) {
PDFImage.resize(rgbBuf, bpc, 3, originalWidth, originalHeight, width,
height, dest, alpha01);
resizeRgbImage(rgbBuf, bpc, originalWidth, originalHeight,
width, height, alpha01, dest);
} else {
rgbPos = 0;
destPos = 0;
@ -1290,12 +1322,5 @@ var LabCS = (function LabCSClosure() {
return LabCS;
})();
// TODO refactor to remove dependency on image.js
function _setCoreImage(coreImage_) {
coreImage = coreImage_;
PDFImage = coreImage_.PDFImage;
}
exports._setCoreImage = _setCoreImage;
exports.ColorSpace = ColorSpace;
}));

104
src/core/image.js
View File

@ -68,6 +68,39 @@ var PDFImage = (function PDFImageClosure() {
return (value < 0 ? 0 : (value > max ? max : value));
}
/**
* Resizes an image mask with 1 component.
* @param {TypedArray} src - The source buffer.
* @param {Number} bpc - Number of bits per component.
* @param {Number} w1 - Original width.
* @param {Number} h1 - Original height.
* @param {Number} w2 - New width.
* @param {Number} h2 - New height.
* @returns {TypedArray} The resized image mask buffer.
*/
function resizeImageMask(src, bpc, w1, h1, w2, h2) {
var length = w2 * h2;
var dest = (bpc <= 8 ? new Uint8Array(length) :
(bpc <= 16 ? new Uint16Array(length) : new Uint32Array(length)));
var xRatio = w1 / w2;
var yRatio = h1 / h2;
var i, j, py, newIndex = 0, oldIndex;
var xScaled = new Uint16Array(w2);
var w1Scanline = w1;
for (i = 0; i < w2; i++) {
xScaled[i] = Math.floor(i * xRatio);
}
for (i = 0; i < h2; i++) {
py = Math.floor(i * yRatio) * w1Scanline;
for (j = 0; j < w2; j++) {
oldIndex = py + xScaled[j];
dest[newIndex++] = src[oldIndex];
}
}
return dest;
}
function PDFImage(xref, res, image, inline, smask, mask, isMask) {
this.image = image;
var dict = image.dict;
@ -209,66 +242,6 @@ var PDFImage = (function PDFImageClosure() {
});
};
/**
* Resize an image using the nearest neighbor algorithm. Currently only
* supports one and three component images.
* @param {TypedArray} pixels The original image with one component.
* @param {Number} bpc Number of bits per component.
* @param {Number} components Number of color components, 1 or 3 is supported.
* @param {Number} w1 Original width.
* @param {Number} h1 Original height.
* @param {Number} w2 New width.
* @param {Number} h2 New height.
* @param {TypedArray} dest (Optional) The destination buffer.
* @param {Number} alpha01 (Optional) Size reserved for the alpha channel.
* @return {TypedArray} Resized image data.
*/
PDFImage.resize = function PDFImage_resize(pixels, bpc, components,
w1, h1, w2, h2, dest, alpha01) {
if (components !== 1 && components !== 3) {
error('Unsupported component count for resizing.');
}
var length = w2 * h2 * components;
var temp = dest ? dest : (bpc <= 8 ? new Uint8Array(length) :
(bpc <= 16 ? new Uint16Array(length) : new Uint32Array(length)));
var xRatio = w1 / w2;
var yRatio = h1 / h2;
var i, j, py, newIndex = 0, oldIndex;
var xScaled = new Uint16Array(w2);
var w1Scanline = w1 * components;
if (alpha01 !== 1) {
alpha01 = 0;
}
for (j = 0; j < w2; j++) {
xScaled[j] = Math.floor(j * xRatio) * components;
}
if (components === 1) {
for (i = 0; i < h2; i++) {
py = Math.floor(i * yRatio) * w1Scanline;
for (j = 0; j < w2; j++) {
oldIndex = py + xScaled[j];
temp[newIndex++] = pixels[oldIndex];
}
}
} else if (components === 3) {
for (i = 0; i < h2; i++) {
py = Math.floor(i * yRatio) * w1Scanline;
for (j = 0; j < w2; j++) {
oldIndex = py + xScaled[j];
temp[newIndex++] = pixels[oldIndex++];
temp[newIndex++] = pixels[oldIndex++];
temp[newIndex++] = pixels[oldIndex++];
newIndex += alpha01;
}
}
}
return temp;
};
PDFImage.createMask =
function PDFImage_createMask(imgArray, width, height,
imageIsFromDecodeStream, inverseDecode) {
@ -439,8 +412,8 @@ var PDFImage = (function PDFImageClosure() {
alphaBuf = new Uint8Array(sw * sh);
smask.fillGrayBuffer(alphaBuf);
if (sw !== width || sh !== height) {
alphaBuf = PDFImage.resize(alphaBuf, smask.bpc, 1, sw, sh, width,
height);
alphaBuf = resizeImageMask(alphaBuf, smask.bpc, sw, sh,
width, height);
}
} else if (mask) {
if (mask instanceof PDFImage) {
@ -456,8 +429,8 @@ var PDFImage = (function PDFImageClosure() {
}
if (sw !== width || sh !== height) {
alphaBuf = PDFImage.resize(alphaBuf, mask.bpc, 1, sw, sh, width,
height);
alphaBuf = resizeImageMask(alphaBuf, mask.bpc, sw, sh,
width, height);
}
} else if (isArray(mask)) {
// Color key mask: if any of the compontents are outside the range
@ -693,7 +666,4 @@ var PDFImage = (function PDFImageClosure() {
})();
exports.PDFImage = PDFImage;
// TODO refactor to remove dependency on colorspace.js
coreColorSpace._setCoreImage(exports);
}));