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Optimizes Blurhash generation

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This commit is contained in:
Vitor Pamplona 2024-05-31 14:24:55 -04:00
parent 071da53a6a
commit 3a9637ccb9
6 changed files with 508 additions and 65 deletions
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20
app/src/main/java/com/vitorpamplona/amethyst/service/BlurHashImage.kt
View File

@ -31,9 +31,9 @@ import coil.fetch.FetchResult
import coil.fetch.Fetcher
import coil.request.ImageRequest
import coil.request.Options
import com.vitorpamplona.amethyst.commons.preview.BlurHashDecoder
import java.net.URLDecoder
import java.net.URLEncoder
import kotlin.math.roundToInt
@Stable
class BlurHashFetcher(
@ -43,23 +43,9 @@ class BlurHashFetcher(
override suspend fun fetch(): FetchResult {
checkNotInMainThread()
val encodedHash = data.toString().removePrefix("bluehash:")
val hash = URLDecoder.decode(encodedHash, "utf-8")
val hash = URLDecoder.decode(data.toString().removePrefix("bluehash:"), "utf-8")
val aspectRatio = BlurHashDecoder.aspectRatio(hash) ?: 1.0f
val preferredWidth = 100
val bitmap =
BlurHashDecoder.decode(
hash,
preferredWidth,
(preferredWidth * (1 / aspectRatio)).roundToInt(),
)
if (bitmap == null) {
throw Exception("Unable to convert Bluehash $hash")
}
val bitmap = BlurHashDecoder.decodeKeepAspectRatio(hash, 25) ?: throw Exception("Unable to convert Bluehash $data")
return DrawableResult(
drawable = bitmap.toDrawable(options.context.resources),

16
app/src/main/java/com/vitorpamplona/amethyst/ui/components/ZoomableContentView.kt
View File

@ -665,14 +665,16 @@ fun DisplayBlurHash(
if (blurhash == null) return
val context = LocalContext.current
val model =
remember {
BlurHashRequester.imageRequest(
context,
blurhash,
)
}
AsyncImage(
model =
remember {
BlurHashRequester.imageRequest(
context,
blurhash,
)
},
model = model,
contentDescription = description,
contentScale = contentScale,
modifier = modifier,

56
benchmark/src/androidTest/java/com/vitorpamplona/amethyst/benchmark/BlurhashBenchmark.kt Normal file
View File

@ -0,0 +1,56 @@
/**
* Copyright (c) 2024 Vitor Pamplona
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
* Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package com.vitorpamplona.amethyst.benchmark
import androidx.benchmark.junit4.BenchmarkRule
import androidx.benchmark.junit4.measureRepeated
import androidx.test.ext.junit.runners.AndroidJUnit4
import com.vitorpamplona.amethyst.commons.preview.BlurHashDecoder
import org.junit.Rule
import org.junit.Test
import org.junit.runner.RunWith
@RunWith(AndroidJUnit4::class)
class BlurhashBenchmark {
@get:Rule
val benchmarkRule = BenchmarkRule()
val warmHex = "[45#Y7_2^-xt%OSb%4S0-qt0xbotaRInV|M{RlD~M{M_IVIUNHM{M{M{M{RjNGRkoyj]o[t8tPt8"
val testHex = "|NHL-]~pabocs+jDM{j?of4T9ZR+WBWZbdR-WCog04ITn\$t6t6t6t6oJoLZ}?bIUWBs:M{WCogRjs:s+o#R+WBoft7axWBx]IV%LogM{t5xaWBay%KRjxus.WCNGWWt7j[j]s+R-S5ofjYV@j[ofD%t8RPoJt7t7R*WCof"
@Test
fun testAspectRatio() {
BlurHashDecoder.aspectRatio(warmHex)
benchmarkRule.measureRepeated {
BlurHashDecoder.aspectRatio(testHex)
}
}
@Test
fun testDecoder() {
BlurHashDecoder.decodeKeepAspectRatio(warmHex, 50)
benchmarkRule.measureRepeated {
BlurHashDecoder.decodeKeepAspectRatio(testHex, 50)
}
}
}

63
commons/src/androidTest/java/com/vitorpamplona/amethyst/commons/preview/BlurhashTest.kt Normal file
View File

@ -0,0 +1,63 @@
/**
* Copyright (c) 2024 Vitor Pamplona
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
* Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package com.vitorpamplona.amethyst.commons.preview
import junit.framework.TestCase.assertTrue
import org.junit.Assert
import org.junit.Test
import kotlin.math.roundToInt
class BlurhashTest {
val warmHex = "[45#Y7_2^-xt%OSb%4S0-qt0xbotaRInV|M{RlD~M{M_IVIUNHM{M{M{M{RjNGRkoyj]o[t8tPt8"
val testHex = "|NHL-]~pabocs+jDM{j?of4T9ZR+WBWZbdR-WCog04ITn\$t6t6t6t6oJoLZ}?bIUWBs:M{WCogRjs:s+o#R+WBoft7axWBx]IV%LogM{t5xaWBay%KRjxus.WCNGWWt7j[j]s+R-S5ofjYV@j[ofD%t8RPoJt7t7R*WCof"
@Test
fun testAspectRatioWarm() {
Assert.assertEquals(0.44444445f, BlurHashDecoderOld.aspectRatio(warmHex)!!, 0.001f)
Assert.assertEquals(0.44444445f, BlurHashDecoder.aspectRatio(warmHex)!!, 0.001f)
}
@Test
fun testDecoderWarm() {
val aspectRatio = BlurHashDecoder.aspectRatio(warmHex) ?: 1.0f
val bmp1 = BlurHashDecoderOld.decode(warmHex, 100, (100 * (1 / aspectRatio)).roundToInt())
val bmp2 = BlurHashDecoder.decodeKeepAspectRatio(warmHex, 100)
assertTrue(bmp1!!.sameAs(bmp2!!))
}
@Test
fun testAspectRatioTest() {
Assert.assertEquals(1.0f, BlurHashDecoderOld.aspectRatio(testHex)!!)
Assert.assertEquals(1.0f, BlurHashDecoder.aspectRatio(testHex)!!)
}
@Test
fun testDecoderTest() {
val aspectRatio = BlurHashDecoder.aspectRatio(testHex) ?: 1.0f
val bmp1 = BlurHashDecoderOld.decode(testHex, 100, (100 * (1 / aspectRatio)).roundToInt())
val bmp2 = BlurHashDecoder.decodeKeepAspectRatio(testHex, 100)
assertTrue(bmp1!!.sameAs(bmp2!!))
}
}

100
app/src/main/java/com/vitorpamplona/amethyst/service/BlurHashDecoder.kt → commons/src/main/java/com/vitorpamplona/amethyst/commons/preview/BlurHashDecoder.kt
View File

@ -18,12 +18,13 @@
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package com.vitorpamplona.amethyst.service
package com.vitorpamplona.amethyst.commons.preview
import android.graphics.Bitmap
import android.graphics.Color
import kotlin.math.cos
import kotlin.math.pow
import kotlin.math.roundToInt
import kotlin.math.withSign
object BlurHashDecoder {
@ -49,7 +50,7 @@ object BlurHashDecoder {
if (blurHash == null || blurHash.length < 6) {
return null
}
val numCompEnc = decode83(blurHash, 0, 1)
val numCompEnc = decode83At(blurHash, 0)
val numCompX = (numCompEnc % 9) + 1
val numCompY = (numCompEnc / 9) + 1
if (blurHash.length != 4 + 2 * numCompX * numCompY) {
@ -66,40 +67,48 @@ object BlurHashDecoder {
* if the cache does not exist yet it will be created and populated with new calculations. By
* default it is true.
*/
fun decode(
fun decodeKeepAspectRatio(
blurHash: String?,
width: Int,
height: Int,
punch: Float = 1f,
useCache: Boolean = true,
): Bitmap? {
checkNotInMainThread()
if (blurHash == null || blurHash.length < 6) {
return null
}
val numCompEnc = decode83(blurHash, 0, 1)
val numCompEnc = decode83At(blurHash, 0)
val numCompX = (numCompEnc % 9) + 1
val numCompY = (numCompEnc / 9) + 1
if (blurHash.length != 4 + 2 * numCompX * numCompY) {
return null
}
val maxAcEnc = decode83(blurHash, 1, 2)
val maxAc = (maxAcEnc + 1) / 166f
val height = (100 * (1 / (numCompX.toFloat() / numCompY.toFloat()))).roundToInt()
val maxAc = (decode83At(blurHash, 1) + 1) / 166f
val colors =
Array(numCompX * numCompY) { i ->
if (i == 0) {
val colorEnc = decode83(blurHash, 2, 6)
decodeDc(colorEnc)
decodeDc(decode83(blurHash, 2, 6))
} else {
val from = 4 + i * 2
val colorEnc = decode83(blurHash, from, from + 2)
decodeAc(colorEnc, maxAc * punch)
decodeAc(decode83Fixed2(blurHash, 4 + i * 2), maxAc)
}
}
return composeBitmap(width, height, numCompX, numCompY, colors, useCache)
}
private fun decode83At(
str: String,
at: Int = 0,
): Int {
return charMap[str[at].code]
}
private fun decode83Fixed2(
str: String,
from: Int = 0,
): Int {
return charMap[str[from].code] * 83 + charMap[str[from + 1].code]
}
private fun decode83(
str: String,
from: Int = 0,
@ -107,10 +116,7 @@ object BlurHashDecoder {
): Int {
var result = 0
for (i in from until to) {
val index = charMap[str[i]] ?: -1
if (index != -1) {
result = result * 83 + index
}
result = result * 83 + charMap[str[i].code]
}
return result
}
@ -161,15 +167,20 @@ object BlurHashDecoder {
val cosinesX = getArrayForCosinesX(calculateCosX, width, numCompX)
val calculateCosY = !useCache || !cacheCosinesY.containsKey(height * numCompY)
val cosinesY = getArrayForCosinesY(calculateCosY, height, numCompY)
var r = 0.0f
var g = 0.0f
var b = 0.0f
for (y in 0 until height) {
for (x in 0 until width) {
var r = 0f
var g = 0f
var b = 0f
r = 0.0f
g = 0.0f
b = 0.0f
for (j in 0 until numCompY) {
for (i in 0 until numCompX) {
val cosX = cosinesX.getCos(calculateCosX, i, numCompX, x, width)
val cosY = cosinesY.getCos(calculateCosY, j, numCompY, y, height)
val cosY = cosinesY[j + numCompY * y]
val cosX = cosinesX[i + numCompX * x]
val basis = (cosX * cosY).toFloat()
val color = colors[j * numCompX + i]
r += color[0] * basis
@ -177,6 +188,7 @@ object BlurHashDecoder {
b += color[2] * basis
}
}
imageArray[x + width * y] = Color.rgb(linearToSrgb(r), linearToSrgb(g), linearToSrgb(b))
}
}
@ -189,7 +201,13 @@ object BlurHashDecoder {
numCompY: Int,
) = when {
calculate -> {
DoubleArray(height * numCompY).also { cacheCosinesY[height * numCompY] = it }
DoubleArray(height * numCompY) {
val y = it / numCompY
val j = it % numCompY
cos(Math.PI * y * j / height)
}.also {
cacheCosinesY[height * numCompY] = it
}
}
else -> {
cacheCosinesY[height * numCompY]!!
@ -202,24 +220,15 @@ object BlurHashDecoder {
numCompX: Int,
) = when {
calculate -> {
DoubleArray(width * numCompX).also { cacheCosinesX[width * numCompX] = it }
DoubleArray(width * numCompX) {
val x = it / numCompX
val i = it % numCompX
cos(Math.PI * x * i / width)
}.also { cacheCosinesX[width * numCompX] = it }
}
else -> cacheCosinesX[width * numCompX]!!
}
private fun DoubleArray.getCos(
calculate: Boolean,
x: Int,
numComp: Int,
y: Int,
size: Int,
): Double {
if (calculate) {
this[x + numComp * y] = cos(Math.PI * y * x / size)
}
return this[x + numComp * y]
}
private fun linearToSrgb(value: Float): Int {
val v = value.coerceIn(0f, 1f)
return if (v <= 0.0031308f) {
@ -229,6 +238,11 @@ object BlurHashDecoder {
}
}
private val linToSrgbApproximation =
Array(255) {
linearToSrgb(it / 255f)
}
private val charMap =
listOf(
'0',
@ -315,6 +329,10 @@ object BlurHashDecoder {
'}',
'~',
)
.mapIndexed { i, c -> c to i }
.toMap()
.mapIndexed { i, c -> c.code to i }
.toMap().let { charMap ->
Array(255) {
charMap[it] ?: 0
}
}
}

318
commons/src/main/java/com/vitorpamplona/amethyst/commons/preview/BlurHashDecoderOld.kt Normal file
View File

@ -0,0 +1,318 @@
/**
* Copyright (c) 2024 Vitor Pamplona
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
* Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package com.vitorpamplona.amethyst.commons.preview
import android.graphics.Bitmap
import android.graphics.Color
import kotlin.math.cos
import kotlin.math.pow
import kotlin.math.withSign
object BlurHashDecoderOld {
// cache Math.cos() calculations to improve performance.
// The number of calculations can be huge for many bitmaps: width * height * numCompX * numCompY *
// 2 * nBitmaps
// the cache is enabled by default, it is recommended to disable it only when just a few images
// are displayed
private val cacheCosinesX = HashMap<Int, DoubleArray>()
private val cacheCosinesY = HashMap<Int, DoubleArray>()
/**
* Clear calculations stored in memory cache. The cache is not big, but will increase when many
* image sizes are used, if the app needs memory it is recommended to clear it.
*/
fun clearCache() {
cacheCosinesX.clear()
cacheCosinesY.clear()
}
/** Returns width/height */
fun aspectRatio(blurHash: String?): Float? {
if (blurHash == null || blurHash.length < 6) {
return null
}
val numCompEnc = decode83(blurHash, 0, 1)
val numCompX = (numCompEnc % 9) + 1
val numCompY = (numCompEnc / 9) + 1
if (blurHash.length != 4 + 2 * numCompX * numCompY) {
return null
}
return numCompX.toFloat() / numCompY.toFloat()
}
/**
* Decode a blur hash into a new bitmap.
*
* @param useCache use in memory cache for the calculated math, reused by images with same size.
* if the cache does not exist yet it will be created and populated with new calculations. By
* default it is true.
*/
fun decode(
blurHash: String?,
width: Int,
height: Int,
punch: Float = 1f,
useCache: Boolean = true,
): Bitmap? {
if (blurHash == null || blurHash.length < 6) {
return null
}
val numCompEnc = decode83(blurHash, 0, 1)
val numCompX = (numCompEnc % 9) + 1
val numCompY = (numCompEnc / 9) + 1
if (blurHash.length != 4 + 2 * numCompX * numCompY) {
return null
}
val maxAcEnc = decode83(blurHash, 1, 2)
val maxAc = (maxAcEnc + 1) / 166f
val colors =
Array(numCompX * numCompY) { i ->
if (i == 0) {
val colorEnc = decode83(blurHash, 2, 6)
decodeDc(colorEnc)
} else {
val from = 4 + i * 2
val colorEnc = decode83(blurHash, from, from + 2)
decodeAc(colorEnc, maxAc * punch)
}
}
return composeBitmap(width, height, numCompX, numCompY, colors, useCache)
}
private fun decode83(
str: String,
from: Int = 0,
to: Int = str.length,
): Int {
var result = 0
for (i in from until to) {
val index = charMap[str[i]] ?: -1
if (index != -1) {
result = result * 83 + index
}
}
return result
}
private fun decodeDc(colorEnc: Int): FloatArray {
val r = colorEnc shr 16
val g = (colorEnc shr 8) and 255
val b = colorEnc and 255
return floatArrayOf(srgbToLinear(r), srgbToLinear(g), srgbToLinear(b))
}
private fun srgbToLinear(colorEnc: Int): Float {
val v = colorEnc / 255f
return if (v <= 0.04045f) {
(v / 12.92f)
} else {
((v + 0.055f) / 1.055f).pow(2.4f)
}
}
private fun decodeAc(
value: Int,
maxAc: Float,
): FloatArray {
val r = value / (19 * 19)
val g = (value / 19) % 19
val b = value % 19
return floatArrayOf(
signedPow2((r - 9) / 9.0f) * maxAc,
signedPow2((g - 9) / 9.0f) * maxAc,
signedPow2((b - 9) / 9.0f) * maxAc,
)
}
private fun signedPow2(value: Float) = value.pow(2f).withSign(value)
private fun composeBitmap(
width: Int,
height: Int,
numCompX: Int,
numCompY: Int,
colors: Array<FloatArray>,
useCache: Boolean,
): Bitmap {
// use an array for better performance when writing pixel colors
val imageArray = IntArray(width * height)
val calculateCosX = !useCache || !cacheCosinesX.containsKey(width * numCompX)
val cosinesX = getArrayForCosinesX(calculateCosX, width, numCompX)
val calculateCosY = !useCache || !cacheCosinesY.containsKey(height * numCompY)
val cosinesY = getArrayForCosinesY(calculateCosY, height, numCompY)
for (y in 0 until height) {
for (x in 0 until width) {
var r = 0f
var g = 0f
var b = 0f
for (j in 0 until numCompY) {
for (i in 0 until numCompX) {
val cosX = cosinesX.getCos(calculateCosX, i, numCompX, x, width)
val cosY = cosinesY.getCos(calculateCosY, j, numCompY, y, height)
val basis = (cosX * cosY).toFloat()
val color = colors[j * numCompX + i]
r += color[0] * basis
g += color[1] * basis
b += color[2] * basis
}
}
imageArray[x + width * y] = Color.rgb(linearToSrgb(r), linearToSrgb(g), linearToSrgb(b))
}
}
return Bitmap.createBitmap(imageArray, width, height, Bitmap.Config.ARGB_8888)
}
private fun getArrayForCosinesY(
calculate: Boolean,
height: Int,
numCompY: Int,
) = when {
calculate -> {
DoubleArray(height * numCompY).also { cacheCosinesY[height * numCompY] = it }
}
else -> {
cacheCosinesY[height * numCompY]!!
}
}
private fun getArrayForCosinesX(
calculate: Boolean,
width: Int,
numCompX: Int,
) = when {
calculate -> {
DoubleArray(width * numCompX).also { cacheCosinesX[width * numCompX] = it }
}
else -> cacheCosinesX[width * numCompX]!!
}
private fun DoubleArray.getCos(
calculate: Boolean,
x: Int,
numComp: Int,
y: Int,
size: Int,
): Double {
if (calculate) {
this[x + numComp * y] = cos(Math.PI * y * x / size)
}
return this[x + numComp * y]
}
private fun linearToSrgb(value: Float): Int {
val v = value.coerceIn(0f, 1f)
return if (v <= 0.0031308f) {
(v * 12.92f * 255f + 0.5f).toInt()
} else {
((1.055f * v.pow(1 / 2.4f) - 0.055f) * 255 + 0.5f).toInt()
}
}
private val charMap =
listOf(
'0',
'1',
'2',
'3',
'4',
'5',
'6',
'7',
'8',
'9',
'A',
'B',
'C',
'D',
'E',
'F',
'G',
'H',
'I',
'J',
'K',
'L',
'M',
'N',
'O',
'P',
'Q',
'R',
'S',
'T',
'U',
'V',
'W',
'X',
'Y',
'Z',
'a',
'b',
'c',
'd',
'e',
'f',
'g',
'h',
'i',
'j',
'k',
'l',
'm',
'n',
'o',
'p',
'q',
'r',
's',
't',
'u',
'v',
'w',
'x',
'y',
'z',
'#',
'$',
'%',
'*',
'+',
',',
'-',
'.',
':',
';',
'=',
'?',
'@',
'[',
']',
'^',
'_',
'{',
'|',
'}',
'~',
)
.mapIndexed { i, c -> c to i }
.toMap()
}