Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 | import type { ByteArray } from 'dicom-parser';
import type { Types } from '@cornerstonejs/core';
async function decodeRLE(
imageFrame: Types.IImageFrame,
pixelData: ByteArray
): Promise<Types.IImageFrame> {
if (imageFrame.bitsAllocated === 8) {
if (imageFrame.planarConfiguration) {
return decode8Planar(imageFrame, pixelData);
}
return decode8(imageFrame, pixelData);
} else if (imageFrame.bitsAllocated === 16) {
return decode16(imageFrame, pixelData);
}
throw new Error('unsupported pixel format for RLE');
}
function decode8(imageFrame: Types.IImageFrame, pixelData: ByteArray) {
const frameData = pixelData;
const frameSize = imageFrame.rows * imageFrame.columns;
const outFrame = new ArrayBuffer(frameSize * imageFrame.samplesPerPixel);
const header = new DataView(frameData.buffer, frameData.byteOffset);
const data = new Int8Array(frameData.buffer, frameData.byteOffset);
const out = new Int8Array(outFrame);
let outIndex = 0;
const numSegments = header.getInt32(0, true);
for (let s = 0; s < numSegments; ++s) {
outIndex = s;
let inIndex = header.getInt32((s + 1) * 4, true);
let maxIndex = header.getInt32((s + 2) * 4, true);
if (maxIndex === 0) {
maxIndex = frameData.length;
}
const endOfSegment = frameSize * numSegments;
while (inIndex < maxIndex) {
const n = data[inIndex++];
if (n >= 0 && n <= 127) {
// copy n bytes
for (let i = 0; i < n + 1 && outIndex < endOfSegment; ++i) {
out[outIndex] = data[inIndex++];
outIndex += imageFrame.samplesPerPixel;
}
} else if (n <= -1 && n >= -127) {
const value = data[inIndex++];
// run of n bytes
for (let j = 0; j < -n + 1 && outIndex < endOfSegment; ++j) {
out[outIndex] = value;
outIndex += imageFrame.samplesPerPixel;
}
} /* else if (n === -128) {
} // do nothing */
}
}
imageFrame.pixelData = new Uint8Array(outFrame);
return imageFrame;
}
function decode8Planar(imageFrame: Types.IImageFrame, pixelData: ByteArray) {
const frameData = pixelData;
const frameSize = imageFrame.rows * imageFrame.columns;
const outFrame = new ArrayBuffer(frameSize * imageFrame.samplesPerPixel);
const header = new DataView(frameData.buffer, frameData.byteOffset);
const data = new Int8Array(frameData.buffer, frameData.byteOffset);
const out = new Int8Array(outFrame);
let outIndex = 0;
const numSegments = header.getInt32(0, true);
for (let s = 0; s < numSegments; ++s) {
outIndex = s * frameSize;
let inIndex = header.getInt32((s + 1) * 4, true);
let maxIndex = header.getInt32((s + 2) * 4, true);
if (maxIndex === 0) {
maxIndex = frameData.length;
}
const endOfSegment = frameSize * numSegments;
while (inIndex < maxIndex) {
const n = data[inIndex++];
if (n >= 0 && n <= 127) {
// copy n bytes
for (let i = 0; i < n + 1 && outIndex < endOfSegment; ++i) {
out[outIndex] = data[inIndex++];
outIndex++;
}
} else if (n <= -1 && n >= -127) {
const value = data[inIndex++];
// run of n bytes
for (let j = 0; j < -n + 1 && outIndex < endOfSegment; ++j) {
out[outIndex] = value;
outIndex++;
}
} /* else if (n === -128) {
} // do nothing */
}
}
imageFrame.pixelData = new Uint8Array(outFrame);
return imageFrame;
}
function decode16(imageFrame: Types.IImageFrame, pixelData: ByteArray) {
const frameData = pixelData;
const frameSize = imageFrame.rows * imageFrame.columns;
const outFrame = new ArrayBuffer(frameSize * imageFrame.samplesPerPixel * 2);
const header = new DataView(frameData.buffer, frameData.byteOffset);
const data = new Int8Array(frameData.buffer, frameData.byteOffset);
const out = new Int8Array(outFrame);
const numSegments = header.getInt32(0, true);
for (let s = 0; s < numSegments; ++s) {
let outIndex = 0;
const highByte = s === 0 ? 1 : 0;
let inIndex = header.getInt32((s + 1) * 4, true);
let maxIndex = header.getInt32((s + 2) * 4, true);
if (maxIndex === 0) {
maxIndex = frameData.length;
}
while (inIndex < maxIndex) {
const n = data[inIndex++];
if (n >= 0 && n <= 127) {
for (let i = 0; i < n + 1 && outIndex < frameSize; ++i) {
out[outIndex * 2 + highByte] = data[inIndex++];
outIndex++;
}
} else if (n <= -1 && n >= -127) {
const value = data[inIndex++];
for (let j = 0; j < -n + 1 && outIndex < frameSize; ++j) {
out[outIndex * 2 + highByte] = value;
outIndex++;
}
} /* else if (n === -128) {
} // do nothing */
}
}
if (imageFrame.pixelRepresentation === 0) {
imageFrame.pixelData = new Uint16Array(outFrame);
} else {
imageFrame.pixelData = new Int16Array(outFrame);
}
return imageFrame;
}
export default decodeRLE;
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