File size: 5,267 Bytes
80bcac8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
177
178
179
180
181
182
183
184
185
186
import { PaddingMode, ConvolutionStep, ImageDataExtended } from '@/types'

export function getPixel(
  image: ImageDataExtended,
  x: number,
  y: number,
  channel: number,
  padding: PaddingMode
): number {
  const { width, height, channels, data } = image

  let px = x
  let py = y

  switch (padding) {
    case 'zero':
      if (px < 0 || px >= width || py < 0 || py >= height) return 0
      break
    case 'replicate':
      px = Math.max(0, Math.min(px, width - 1))
      py = Math.max(0, Math.min(py, height - 1))
      break
    case 'reflect':
      if (px < 0) px = -px
      if (px >= width) px = 2 * width - px - 2
      if (py < 0) py = -py
      if (py >= height) py = 2 * height - py - 2
      px = Math.max(0, Math.min(px, width - 1))
      py = Math.max(0, Math.min(py, height - 1))
      break
    case 'wrap':
      px = ((px % width) + width) % width
      py = ((py % height) + height) % height
      break
  }

  const index = (py * width + px) * channels + channel
  return data[index] / 255
}

export function setPixel(
  image: ImageDataExtended,
  x: number,
  y: number,
  channel: number,
  value: number
): void {
  const { width, channels, data } = image
  if (x < 0 || x >= width || y < 0 || y >= image.height) return
  const index = (y * width + x) * channels + channel
  data[index] = Math.max(0, Math.min(255, Math.round(value * 255)))
}

export function* convolutionSteps(
  image: ImageDataExtended,
  kernel: number[][],
  padding: PaddingMode,
  normalize: boolean,
  onProgress?: (progress: number) => void
): Generator<ConvolutionStep> {
  const { width, height, channels } = image
  const kernelSize = kernel.length
  const halfKernel = Math.floor(kernelSize / 2)

  const totalPixels = width * height * channels
  let processedPixels = 0

  const kernelSum = kernel.flat().reduce((a, b) => a + b, 0)
  const normalizeFactor = normalize && kernelSum !== 0 ? 1 / kernelSum : 1

  const outputData = new Float32Array(width * height * channels)

  for (let y = 0; y < height; y++) {
    for (let x = 0; x < width; x++) {
      for (let c = 0; c < channels; c++) {
        const inputPatch: number[][] = []
        const multiplications: number[][] = []
        let sum = 0

        for (let ky = 0; ky < kernelSize; ky++) {
          const patchRow: number[] = []
          const multRow: number[] = []
          for (let kx = 0; kx < kernelSize; kx++) {
            const px = x + kx - halfKernel
            const py = y + ky - halfKernel
            const pixelValue = getPixel(image, px, py, c, padding)
            const kernelValue = kernel[ky][kx]
            patchRow.push(pixelValue)
            const mult = pixelValue * kernelValue
            multRow.push(mult)
            sum += mult
          }
          inputPatch.push(patchRow)
          multiplications.push(multRow)
        }

        const outputValue = sum
        const normalizedValue = sum * normalizeFactor

        const outputIndex = (y * width + x) * channels + c
        outputData[outputIndex] = normalizedValue

        processedPixels++
        const progress = processedPixels / totalPixels

        yield {
          x,
          y,
          channel: c,
          inputPatch,
          kernel,
          multiplications,
          sum: outputValue,
          outputValue: normalizedValue,
          normalizedValue,
          progress,
        }

        if (onProgress) onProgress(progress)
      }
    }
  }

  // Convert output to ImageData
  const outputImageData = new ImageData(width, height)
  for (let i = 0; i < outputData.length; i++) {
    outputImageData.data[i] = Math.max(0, Math.min(255, Math.round(outputData[i] * 255)))
  }

  // Final yield with complete output
  yield {
    x: -1,
    y: -1,
    channel: -1,
    inputPatch: [],
    kernel,
    multiplications: [],
    sum: 0,
    outputValue: 0,
    normalizedValue: 0,
    progress: 1,
  }
}

export function convolveImage(
  imageData: ImageData,
  kernel: number[][],
  padding: PaddingMode = 'zero',
  normalize: boolean = true
): ImageData {
  const extended: ImageDataExtended = {
    data: imageData.data,
    width: imageData.width,
    height: imageData.height,
    channels: 4,
  }

  const { width, height } = imageData
  const kernelSize = kernel.length
  const halfKernel = Math.floor(kernelSize / 2)
  const kernelSum = kernel.flat().reduce((a, b) => a + b, 0)
  const normalizeFactor = normalize && kernelSum !== 0 ? 1 / kernelSum : 1

  const outputData = new Uint8ClampedArray(imageData.data.length)

  for (let y = 0; y < height; y++) {
    for (let x = 0; x < width; x++) {
      for (let c = 0; c < 3; c++) {
        let sum = 0
        for (let ky = 0; ky < kernelSize; ky++) {
          for (let kx = 0; kx < kernelSize; kx++) {
            const px = x + kx - halfKernel
            const py = y + ky - halfKernel
            const pixelValue = getPixel(extended, px, py, c, padding)
            sum += pixelValue * kernel[ky][kx]
          }
        }
        const outputIndex = (y * width + x) * 4 + c
        outputData[outputIndex] = Math.max(0, Math.min(255, Math.round(sum * normalizeFactor * 255)))
      }
      outputData[(y * width + x) * 4 + 3] = 255
    }
  }

  return new ImageData(outputData, imageData.width, imageData.height)
}