2a:null 2b:["$","title",null,{"children":"The ColorChecker | Jake Weary | Observable"}] 30:[{"id":"42d8d5dd72ec5a232fcb55f7e324cae6099ab2e5d2de8df1138110398b6731f2aefda19875781d18acf6645890d0d555cebd85aecac3fc129675773d7dfb5ac0","href":"https://static.observableusercontent.com/files/42d8d5dd72ec5a232fcb55f7e324cae6099ab2e5d2de8df1138110398b6731f2aefda19875781d18acf6645890d0d555cebd85aecac3fc129675773d7dfb5ac0","name":"ColorChecker24_After_Nov2014.txt","type":"text/plain","lastModified":1602914519394.539,"size":946}] 2e:{"id":"4e5e79def1be988f","slug":"the-colorchecker","title":"The ColorChecker","thumbnail":"e103909621ce991d84588f113daa26405b8313e9f69bc0ae5dd04fc5ccecde8f","access_level":"public","create_time":"$D2020-10-17T04:18:41.718Z","update_time":"$D2020-10-28T14:43:32.712Z","view_time":null,"first_public_time":"$D2020-10-17T05:31:12.411Z","has_unpublished_edits":null,"fork":false,"stars":0,"starred":false,"owner":{"type":"team","id":"42feee7e8a97c31b","login":"thepheer","name":"Jake Weary","avatar_url":"https://avatars-next.observableusercontent.com/2fca8f824ca42d309128821f13d740ecfe8bd493736aacfe4b88bd32a0b2f0a9","tier":"starter_2024"},"version":609,"publish_version":609,"role":null,"authored":false,"authors":[{"type":"individual","id":"f8146b5732c6beb1","login":"thepheer","name":"Jake Weary","avatar_url":"https://avatars-next.observableusercontent.com/2fca8f824ca42d309128821f13d740ecfe8bd493736aacfe4b88bd32a0b2f0a9","tier":null}],"members":[{"type":"individual","id":"f8146b5732c6beb1","login":"thepheer","name":"Jake Weary","avatar_url":"https://avatars-next.observableusercontent.com/2fca8f824ca42d309128821f13d740ecfe8bd493736aacfe4b88bd32a0b2f0a9","tier":null,"role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"lapsed":null,"subscribed":null,"forks":0,"collection":null,"type":"notebook","body":{"titling":"auto","title":"The ColorChecker","cells":[{"id":0,"value":"md`# The ColorChecker`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":148,"value":"html`${colors_sRGB.map(hex).flatMap((hex, i) => [\n html``,\n i%6 == 5 ? html`
` : ''\n])}`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":480,"value":"// html`

${colors_sRGB.map(rgb => `vec3(${rgb.map(n => n.toFixed(3)).join(', ')})`).join(',\\n')}

`","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":169,"value":"md`## Data`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":132,"value":"colors_sRGB = colors_XYZ_D50.map(xyz => mxv(XYZ_to_sRGB_D65, sxv(1/100, xyz)).map(saturate).map(sRGB_EOTF))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":95,"value":"colors_XYZ_D50 = colors_Lab_D50.map(Lab_to_XYZ(CIE1931_D65))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":18,"value":"colors_Lab_D50 = {\n const spec = await FileAttachment('ColorChecker24_After_Nov2014.txt').text()\n return spec.replace(/,/g, '.').split('\\n').slice(15, 15+24)\n .map((_, i, a) => a[(i%6)*4 + Math.floor(i/6)]) // transpose\n .map(l => l.split('\\t').slice(1).map(Number))\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":174,"value":"md`## Color conversion`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":83,"value":"Lab_to_XYZ = r => ([L, a, b]) => {\n const Lʹ = (L + 16)/116\n const 𝑓 = t => t > 6/29 ? t**3 : 108/841*(t - 4/29)\n return vxv(r, [Lʹ + a/500, Lʹ, Lʹ - b/200].map(𝑓))\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":62,"value":"xyY_to_XYZ = ([x, y, Y]) => [x*Y/y, Y, (1-x-y)*Y/y]","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":44,"value":"sRGB_EOTF = n => n<=0.0031308 ? n*12.92 : (n**(1/2.4))*1.055-0.055","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":42,"value":"sRGB_EOTF_inv = n => n<=0.04045 ? n/12.92 : ((n+0.055)/1.055)**2.4","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":324,"value":"md`### XYZ → sRGB matrices`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":124,"value":"XYZ_to_sRGB_D50 = [\n [ 3.1338561, -1.6168667, -0.4906146 ],\n [ -0.9787684, 1.9161415, 0.0334540 ],\n [ 0.0719453, -0.2289914, 1.4052427 ]\n]","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":125,"value":"XYZ_to_sRGB_D65 = [\n [ 3.2404542, -1.5371385, -0.4985314 ],\n [ -0.9692660, 1.8760108, 0.0415560 ],\n [ 0.0556434, -0.2040259, 1.0572252 ]\n]","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":319,"value":"md`### Standard illuminants`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":64,"value":"CIE1931_D50 = xyY_to_XYZ([0.34567, 0.35850, 100.0])","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":521,"value":"CIE1931_D65 = xyY_to_XYZ([0.31271, 0.32902, 100.0])","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":186,"value":"md`## Linear algebra`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":452,"value":"dot = (v, vʹ) => vxv(v, vʹ).reduce((s, sʹ) => s + sʹ)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":534,"value":"sxv = (s, v) => v.map(sʹ => s*sʹ)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":14,"value":"vxv = (v, vʹ) => v.map((s, i) => s*vʹ[i])","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":5,"value":"mxv = (m, v) => m.map(vʹ => dot(v, vʹ))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":194,"value":"md`## Misc.`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":200,"value":"saturate = n => Math.max(0, Math.min(1, n))","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":152,"value":"hex = {\n const u8 = f => 0.5 + 255*f\n const u32 = (r, g, b) => u8(r)<<16 | u8(g)<<8 | u8(b)\n return ([r, g, b]) => '#' + u32(r, g, b).toString(16).padStart(6, '0')\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W30","stdlib":"1"}} 2f:"$2e:body"