mirror of https://github.com/Nheko-Reborn/nheko
Nicolas Werner
5 years ago
parent
328a3c7ebd
commit
0fc98b2692
@ -0,0 +1,42 @@ |
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#include "BlurhashProvider.h" |
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#include <algorithm> |
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#include <QUrl> |
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#include "blurhash.hpp" |
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QImage |
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BlurhashProvider::requestImage(const QString &id, QSize *size, const QSize &requestedSize) |
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{ |
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QSize sz = requestedSize; |
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if (sz.width() < 1 || sz.height() < 1) |
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return QImage(); |
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if (size) |
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*size = sz; |
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auto decoded = blurhash::decode( |
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QUrl::fromPercentEncoding(id.toUtf8()).toStdString(), sz.width(), sz.height()); |
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if (decoded.image.empty()) { |
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*size = QSize(); |
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return QImage(); |
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} |
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QImage image(sz, QImage::Format_RGB888); |
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for (int y = 0; y < sz.height(); y++) { |
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for (int x = 0; x < sz.width(); x++) { |
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int base = (y * sz.width() + x) * 3; |
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image.setPixel(x, |
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y, |
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qRgb(decoded.image[base], |
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decoded.image[base + 1], |
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decoded.image[base + 2])); |
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} |
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} |
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// std::copy(decoded.image.begin(), decoded.image.end(), image.bits());
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return image; |
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} |
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@ -0,0 +1,11 @@ |
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#include <QQuickImageProvider> |
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class BlurhashProvider : public QQuickImageProvider |
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{ |
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public: |
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BlurhashProvider() |
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: QQuickImageProvider(QQuickImageProvider::Image) |
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{} |
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QImage requestImage(const QString &id, QSize *size, const QSize &requestedSize) override; |
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}; |
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@ -0,0 +1,23 @@ |
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Boost Software License - Version 1.0 - August 17th, 2003 |
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Permission is hereby granted, free of charge, to any person or organization |
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obtaining a copy of the software and accompanying documentation covered by |
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this license (the "Software") to use, reproduce, display, distribute, |
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execute, and transmit the Software, and to prepare derivative works of the |
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Software, and to permit third-parties to whom the Software is furnished to |
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do so, all subject to the following: |
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|
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The copyright notices in the Software and this entire statement, including |
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the above license grant, this restriction and the following disclaimer, |
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must be included in all copies of the Software, in whole or in part, and |
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all derivative works of the Software, unless such copies or derivative |
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works are solely in the form of machine-executable object code generated by |
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a source language processor. |
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT |
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SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE |
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FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE, |
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ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
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DEALINGS IN THE SOFTWARE. |
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@ -0,0 +1,472 @@ |
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#include "blurhash.hpp" |
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#include <algorithm> |
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#include <array> |
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#include <cassert> |
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#include <cmath> |
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#include <stdexcept> |
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#ifndef M_PI |
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#define M_PI 3.14159265358979323846 |
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#endif |
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#ifdef DOCTEST_CONFIG_IMPLEMENT_WITH_MAIN |
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#include <doctest.h> |
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#endif |
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using namespace std::literals; |
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namespace { |
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constexpr std::array<char, 84> int_to_b83{ |
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"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz#$%*+,-.:;=?@[]^_{|}~"}; |
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std::string |
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leftPad(std::string str, size_t len) |
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{ |
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if (str.size() >= len) |
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return str; |
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return str.insert(0, len - str.size(), '0'); |
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} |
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constexpr std::array<int, 255> b83_to_int = []() constexpr |
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{ |
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std::array<int, 255> a{}; |
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for (auto &e : a) |
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e = -1; |
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for (int i = 0; i < 83; i++) { |
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a[static_cast<unsigned char>(int_to_b83[i])] = i; |
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} |
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return a; |
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} |
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(); |
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std::string |
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encode83(int value) |
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{ |
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std::string buffer; |
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do { |
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buffer += int_to_b83[value % 83]; |
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} while ((value = value / 83)); |
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std::reverse(buffer.begin(), buffer.end()); |
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return buffer; |
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} |
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struct Components |
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{ |
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int x, y; |
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}; |
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int |
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packComponents(const Components &c) |
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{ |
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return (c.x - 1) + (c.y - 1) * 9; |
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} |
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Components |
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unpackComponents(int c) |
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{ |
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return {c % 9 + 1, c / 9 + 1}; |
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} |
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int |
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decode83(std::string_view value) |
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{ |
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int temp = 0; |
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for (char c : value) |
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if (b83_to_int[static_cast<unsigned char>(c)] < 0) |
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throw std::invalid_argument("invalid character in blurhash"); |
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for (char c : value) |
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temp = temp * 83 + b83_to_int[static_cast<unsigned char>(c)]; |
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return temp; |
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} |
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float |
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decodeMaxAC(int quantizedMaxAC) |
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{ |
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return (quantizedMaxAC + 1) / 166.; |
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} |
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float |
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decodeMaxAC(std::string_view maxAC) |
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{ |
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assert(maxAC.size() == 1); |
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return decodeMaxAC(decode83(maxAC)); |
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} |
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int |
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encodeMaxAC(float maxAC) |
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{ |
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return std::max(0, std::min(82, int(maxAC * 166 - 0.5))); |
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} |
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float |
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srgbToLinear(int value) |
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{ |
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auto srgbToLinearF = [](float x) { |
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if (x <= 0.0f) |
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return 0.0f; |
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else if (x >= 1.0f) |
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return 1.0f; |
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else if (x < 0.04045f) |
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return x / 12.92f; |
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else |
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return std::pow((x + 0.055f) / 1.055f, 2.4f); |
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}; |
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return srgbToLinearF(value / 255.f); |
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} |
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int |
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linearToSrgb(float value) |
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{ |
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auto linearToSrgbF = [](float x) -> float { |
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if (x <= 0.0f) |
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return 0.0f; |
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else if (x >= 1.0f) |
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return 1.0f; |
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else if (x < 0.0031308f) |
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return x * 12.92f; |
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else |
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return std::pow(x, 1.0f / 2.4f) * 1.055f - 0.055f; |
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}; |
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return int(linearToSrgbF(value) * 255.f + 0.5); |
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} |
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struct Color |
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{ |
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float r, g, b; |
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Color &operator*=(float scale) |
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{ |
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r *= scale; |
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g *= scale; |
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b *= scale; |
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return *this; |
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} |
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friend Color operator*(Color lhs, float rhs) { return (lhs *= rhs); } |
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Color &operator/=(float scale) |
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{ |
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r /= scale; |
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g /= scale; |
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b /= scale; |
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return *this; |
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} |
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Color &operator+=(const Color &rhs) |
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{ |
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r += rhs.r; |
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g += rhs.g; |
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b += rhs.b; |
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return *this; |
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} |
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}; |
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Color |
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decodeDC(int value) |
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{ |
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const int intR = value >> 16; |
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const int intG = (value >> 8) & 255; |
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const int intB = value & 255; |
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return {srgbToLinear(intR), srgbToLinear(intG), srgbToLinear(intB)}; |
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} |
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Color |
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decodeDC(std::string_view value) |
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{ |
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assert(value.size() == 4); |
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return decodeDC(decode83(value)); |
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} |
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int |
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encodeDC(const Color &c) |
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{ |
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return (linearToSrgb(c.r) << 16) + (linearToSrgb(c.g) << 8) + linearToSrgb(c.b); |
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} |
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float |
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signPow(float value, float exp) |
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{ |
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return std::copysign(std::pow(std::abs(value), exp), value); |
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} |
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int |
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encodeAC(const Color &c, float maximumValue) |
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{ |
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auto quantR = |
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int(std::max(0., std::min(18., std::floor(signPow(c.r / maximumValue, 0.5) * 9 + 9.5)))); |
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auto quantG = |
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int(std::max(0., std::min(18., std::floor(signPow(c.g / maximumValue, 0.5) * 9 + 9.5)))); |
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auto quantB = |
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int(std::max(0., std::min(18., std::floor(signPow(c.b / maximumValue, 0.5) * 9 + 9.5)))); |
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return quantR * 19 * 19 + quantG * 19 + quantB; |
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} |
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Color |
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decodeAC(int value, float maximumValue) |
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{ |
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auto quantR = value / (19 * 19); |
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auto quantG = (value / 19) % 19; |
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auto quantB = value % 19; |
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return {signPow((float(quantR) - 9) / 9, 2) * maximumValue, |
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signPow((float(quantG) - 9) / 9, 2) * maximumValue, |
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signPow((float(quantB) - 9) / 9, 2) * maximumValue}; |
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} |
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Color |
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decodeAC(std::string_view value, float maximumValue) |
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{ |
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return decodeAC(decode83(value), maximumValue); |
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} |
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Color |
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multiplyBasisFunction(Components components, int width, int height, unsigned char *pixels) |
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{ |
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Color c{}; |
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float normalisation = (components.x == 0 && components.y == 0) ? 1 : 2; |
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for (int y = 0; y < height; y++) { |
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for (int x = 0; x < width; x++) { |
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float basis = std::cos(M_PI * components.x * x / float(width)) * |
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std::cos(M_PI * components.y * y / float(height)); |
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c.r += basis * srgbToLinear(pixels[3 * x + 0 + y * width * 3]); |
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c.g += basis * srgbToLinear(pixels[3 * x + 1 + y * width * 3]); |
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c.b += basis * srgbToLinear(pixels[3 * x + 2 + y * width * 3]); |
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} |
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} |
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float scale = normalisation / (width * height); |
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c *= scale; |
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return c; |
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} |
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} |
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namespace blurhash { |
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Image |
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decode(std::string_view blurhash, size_t width, size_t height) |
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{ |
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Image i{}; |
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if (blurhash.size() < 10) |
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return i; |
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Components components{}; |
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std::vector<Color> values; |
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try { |
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components = unpackComponents(decode83(blurhash.substr(0, 1))); |
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if (components.x < 1 || components.y < 1 || |
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blurhash.size() != size_t(1 + 1 + 4 + (components.x * components.y - 1) * 2)) |
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return {}; |
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auto maxAC = decodeMaxAC(blurhash.substr(1, 1)); |
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Color average = decodeDC(blurhash.substr(2, 4)); |
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values.push_back(average); |
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for (size_t c = 6; c < blurhash.size(); c += 2) |
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values.push_back(decodeAC(blurhash.substr(c, 2), maxAC)); |
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} catch (std::invalid_argument &) { |
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return {}; |
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} |
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i.image.reserve(height * width * 3); |
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for (size_t y = 0; y < height; y++) { |
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for (size_t x = 0; x < width; x++) { |
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Color c{}; |
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for (size_t nx = 0; nx < size_t(components.x); nx++) { |
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for (size_t ny = 0; ny < size_t(components.y); ny++) { |
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float basis = |
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std::cos(M_PI * float(x) * float(nx) / float(width)) * |
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std::cos(M_PI * float(y) * float(ny) / float(height)); |
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c += values[nx + ny * components.x] * basis; |
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} |
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} |
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i.image.push_back(static_cast<unsigned char>(linearToSrgb(c.r))); |
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i.image.push_back(static_cast<unsigned char>(linearToSrgb(c.g))); |
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i.image.push_back(static_cast<unsigned char>(linearToSrgb(c.b))); |
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} |
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} |
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i.height = height; |
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i.width = width; |
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return i; |
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} |
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std::string |
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encode(unsigned char *image, size_t width, size_t height, int components_x, int components_y) |
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{ |
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if (width < 1 || height < 1 || components_x < 1 || components_x > 9 || components_y < 1 || |
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components_y > 9 || !image) |
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return ""; |
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std::vector<Color> factors; |
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factors.reserve(components_x * components_y); |
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for (int y = 0; y < components_y; y++) { |
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for (int x = 0; x < components_x; x++) { |
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factors.push_back(multiplyBasisFunction({x, y}, width, height, image)); |
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} |
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} |
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assert(factors.size() > 0); |
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auto dc = factors.front(); |
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factors.erase(factors.begin()); |
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std::string h; |
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h += leftPad(encode83(packComponents({components_x, components_y})), 1); |
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float maximumValue; |
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if (!factors.empty()) { |
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float actualMaximumValue = 0; |
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for (auto ac : factors) { |
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actualMaximumValue = std::max({ |
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std::abs(ac.r), |
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std::abs(ac.g), |
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std::abs(ac.b), |
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actualMaximumValue, |
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}); |
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} |
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int quantisedMaximumValue = encodeMaxAC(actualMaximumValue); |
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maximumValue = ((float)quantisedMaximumValue + 1) / 166; |
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h += leftPad(encode83(quantisedMaximumValue), 1); |
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} else { |
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maximumValue = 1; |
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h += leftPad(encode83(0), 1); |
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} |
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h += leftPad(encode83(encodeDC(dc)), 4); |
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for (auto ac : factors) |
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h += leftPad(encode83(encodeAC(ac, maximumValue)), 2); |
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return h; |
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} |
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} |
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#ifdef DOCTEST_CONFIG_IMPLEMENT_WITH_MAIN |
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TEST_CASE("component packing") |
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{ |
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for (int i = 0; i < 9 * 9; i++) |
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CHECK(packComponents(unpackComponents(i)) == i); |
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} |
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TEST_CASE("encode83") |
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{ |
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CHECK(encode83(0) == "0"); |
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CHECK(encode83(packComponents({4, 3})) == "L"); |
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CHECK(encode83(packComponents({4, 4})) == "U"); |
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CHECK(encode83(packComponents({8, 4})) == "Y"); |
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CHECK(encode83(packComponents({2, 1})) == "1"); |
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} |
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TEST_CASE("decode83") |
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{ |
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CHECK(packComponents({4, 3}) == decode83("L")); |
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CHECK(packComponents({4, 4}) == decode83("U")); |
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CHECK(packComponents({8, 4}) == decode83("Y")); |
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CHECK(packComponents({2, 1}) == decode83("1")); |
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} |
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TEST_CASE("maxAC") |
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{ |
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for (int i = 0; i < 83; i++) |
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CHECK(encodeMaxAC(decodeMaxAC(i)) == i); |
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CHECK(std::abs(decodeMaxAC("l"sv) - 0.289157f) < 0.00001f); |
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} |
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TEST_CASE("DC") |
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{ |
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CHECK(encode83(encodeDC(decodeDC("MF%n"))) == "MF%n"sv); |
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CHECK(encode83(encodeDC(decodeDC("HV6n"))) == "HV6n"sv); |
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CHECK(encode83(encodeDC(decodeDC("F5]+"))) == "F5]+"sv); |
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CHECK(encode83(encodeDC(decodeDC("Pj0^"))) == "Pj0^"sv); |
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CHECK(encode83(encodeDC(decodeDC("O2?U"))) == "O2?U"sv); |
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} |
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TEST_CASE("AC") |
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{ |
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auto h = "00%#MwS|WCWEM{R*bbWBbH"sv; |
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for (size_t i = 0; i < h.size(); i += 2) { |
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auto s = h.substr(i, 2); |
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const auto maxAC = 0.289157f; |
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CHECK(leftPad(encode83(encodeAC(decodeAC(decode83(s), maxAC), maxAC)), 2) == s); |
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} |
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} |
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TEST_CASE("decode") |
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{ |
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blurhash::Image i1 = blurhash::decode("LEHV6nWB2yk8pyoJadR*.7kCMdnj", 360, 200); |
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CHECK(i1.width == 360); |
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CHECK(i1.height == 200); |
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CHECK(i1.image.size() == i1.height * i1.width * 3); |
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CHECK(i1.image[0] == 135); |
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CHECK(i1.image[1] == 164); |
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CHECK(i1.image[2] == 177); |
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CHECK(i1.image[10000] == 173); |
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CHECK(i1.image[10001] == 176); |
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CHECK(i1.image[10002] == 163); |
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// stbi_write_bmp("test.bmp", i1.width, i1.height, 3, (void *)i1.image.data());
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i1 = blurhash::decode("LGF5]+Yk^6#M@-5c,1J5@[or[Q6.", 360, 200); |
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CHECK(i1.width == 360); |
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CHECK(i1.height == 200); |
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CHECK(i1.image.size() == i1.height * i1.width * 3); |
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// stbi_write_bmp("test2.bmp", i1.width, i1.height, 3, (void *)i1.image.data());
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// invalid inputs
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i1 = blurhash::decode(" LGF5]+Yk^6#M@-5c,1J5@[or[Q6.", 360, 200); |
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CHECK(i1.width == 0); |
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CHECK(i1.height == 0); |
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CHECK(i1.image.size() == 0); |
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i1 = blurhash::decode(" LGF5]+Yk^6#M@-5c,1J5@[or[Q6.", 360, 200); |
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CHECK(i1.width == 0); |
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CHECK(i1.height == 0); |
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CHECK(i1.image.size() == 0); |
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i1 = blurhash::decode("LGF5]+Yk^6# M@-5c,1J5@[or[Q6.", 360, 200); |
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CHECK(i1.width == 0); |
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CHECK(i1.height == 0); |
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CHECK(i1.image.size() == 0); |
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i1 = blurhash::decode("LGF5]+Yk^6# M@-5c,1J5@[or[Q6.", 360, 200); |
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CHECK(i1.width == 0); |
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CHECK(i1.height == 0); |
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CHECK(i1.image.size() == 0); |
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i1 = blurhash::decode("LGF5]+Yk^6# @-5c,1J5@[or[Q6.", 360, 200); |
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CHECK(i1.width == 0); |
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CHECK(i1.height == 0); |
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CHECK(i1.image.size() == 0); |
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i1 = blurhash::decode(" GF5]+Yk^6#M@-5c,1J5@[or[Q6.", 360, 200); |
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CHECK(i1.width == 0); |
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CHECK(i1.height == 0); |
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CHECK(i1.image.size() == 0); |
||||
} |
||||
|
||||
TEST_CASE("encode") |
||||
{ |
||||
CHECK(blurhash::encode(nullptr, 360, 200, 4, 3) == ""); |
||||
|
||||
std::vector<unsigned char> black(360 * 200 * 3, 0); |
||||
CHECK(blurhash::encode(black.data(), 0, 200, 4, 3) == ""); |
||||
CHECK(blurhash::encode(black.data(), 360, 0, 4, 3) == ""); |
||||
CHECK(blurhash::encode(black.data(), 360, 200, 0, 3) == ""); |
||||
CHECK(blurhash::encode(black.data(), 360, 200, 4, 0) == ""); |
||||
CHECK(blurhash::encode(black.data(), 360, 200, 4, 3) == "L00000fQfQfQfQfQfQfQfQfQfQfQ"); |
||||
} |
||||
#endif |
||||
@ -0,0 +1,22 @@ |
||||
#pragma once |
||||
|
||||
#include <string> |
||||
#include <string_view> |
||||
#include <vector> |
||||
|
||||
namespace blurhash { |
||||
struct Image |
||||
{ |
||||
size_t width, height; |
||||
std::vector<unsigned char> image; // pixels rgb
|
||||
}; |
||||
|
||||
// Decode a blurhash to an image with size width*height
|
||||
Image |
||||
decode(std::string_view blurhash, size_t width, size_t height); |
||||
|
||||
// Encode an image of rgb pixels (without padding) with size width*height into a blurhash with x*y
|
||||
// components
|
||||
std::string |
||||
encode(unsigned char *image, size_t width, size_t height, int x, int y); |
||||
} |
||||
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Reference in new issue