ColorLevels::LAB
ColorLevels::LABColorToLAB(
const Magick::ColorRGB &magickLAB)
{
return (LAB{
magickLAB.red() * 100,
(magickLAB.green() * 256) - 100,
(magickLAB.blue() * 256) - 100
});
}
/** \brief Checks if the given Pixel is empty (not used). It is empty, if least significant bits are all 0.
* \param pixel const Pixel& the pixel that should be checked
* \return bool true if pixel is not used until now, else false
*/
bool SteganoHide::isPixelEmpty(const Pixel &pixel) {
Magick::ColorRGB pixelColor = this->steganoImage.pixelColor(pixel.x, pixel.y);
const unsigned char redLeastSignificantBit = convert16BitTo8BitRGB(pixelColor.redQuantum()) % 10;
const unsigned char greenLeastSignificantBit = convert16BitTo8BitRGB(pixelColor.greenQuantum()) % 10;
const unsigned char blueLeastSignificantBit = convert16BitTo8BitRGB(pixelColor.blueQuantum()) % 10;
// std::cout << (int)redLeastSignificantBit << ":" << (int)greenLeastSignificantBit << ":" << (int)blueLeastSignificantBit << std::endl;
return (redLeastSignificantBit == 5 && greenLeastSignificantBit == 5 && blueLeastSignificantBit == 5);
}
Image<Color> imread(const std::string& file) {
Magick::Image image(file);
const size_t w = image.columns();
const size_t h = image.rows();
Magick::PixelPacket* pixels = image.getPixels(0, 0, w, h);
Image<Color> rtn(h, w);
for (size_t i = 0; i < w * h; ++i) {
Magick::ColorRGB p = Magick::ColorRGB(pixels[i]);
rtn(i) = Color(double(p.red()), double(p.green()), double(p.blue()));
}
return rtn;
}
/** \brief Draw a finish pixel at the specified position. The finishpixel has at the least-significant bit of their rgb-value r: 3, g: 0, b: 0
*
* \param &pixel const Pixel a pixel-struct describing the pixel-position where the finish-pixel should be set.
*/
void SteganoHide::drawFinishPixel(const Pixel &pixel) {
Magick::ColorRGB pixelColor = this->steganoImage.pixelColor(pixel.x, pixel.y);
RGB pixelRGB(convert16BitTo8BitRGB(pixelColor.redQuantum()),
convert16BitTo8BitRGB(pixelColor.greenQuantum()),
convert16BitTo8BitRGB(pixelColor.blueQuantum()));
pixelRGB.red = (pixelRGB.red - (pixelRGB.red % 10)) + 3;
pixelRGB.green = pixelRGB.green - (pixelRGB.green % 10);
pixelRGB.blue = pixelRGB.blue - (pixelRGB.blue % 10);
this->steganoImage.pixelColor(pixel.x, pixel.y, Magick::ColorRGB(pixelRGB.toString()));
}
static void compare_colors(const Magick::ColorRGB & expected, const Magick::ColorRGB & observed, bool expected_has_alpha, bool observed_has_alpha ) {
ASSERT_NEAR(expected.red(), observed.red(), 1.1f/(0x1<<8));
ASSERT_NEAR(expected.green(), observed.green(), 1.1f/(0x1<<8));
ASSERT_NEAR(expected.blue(), observed.blue(), 1.1f/(0x1<<8));
if (expected_has_alpha) {
ASSERT_NEAR(expected.alpha(), observed.alpha(), 1.1f / (0x1 << 8));
}
else if (observed_has_alpha) {
ASSERT_NEAR(1.0f, observed.alpha(), 1.1f /(0x1 << 8));
}
}
//Konverterer Magick::Image til QImage
QImage* image_wrapper::to_QImage(Magick::Image& image)
{
qimg_ptr_helper = new QImage(image.columns(), image.rows(), QImage::Format_RGB32);
const Magick::PixelPacket *pixels;
Magick::ColorRGB rgb;
for (int y = 0; y < qimg_ptr_helper->height(); y++) {
pixels = image.getConstPixels(0, y, qimg_ptr_helper->width(), 1);
for (int x = 0; x < qimg_ptr_helper->width(); x++) {
rgb = (*(pixels + x));
qimg_ptr_helper->setPixel(x, y, QColor((int) (255 * rgb.red())
, (int) (255 * rgb.green())
, (int) (255 * rgb.blue())).rgb());
}
}
return qimg_ptr_helper;
}
yuv_image magick_wrapper::xyuv_to_yuv_image_444(const xyuv::conversion_matrix &conversion_matrix) const {
// Analyse the conversion matrix to discover if any plane is not present.
bool has[3] = {false, false, false};
for (uint32_t i = 0; i < 9; i++) {
has[i / 3] = has[i / 3] || (conversion_matrix.rgb_to_yuv[i] != static_cast<pixel_quantum>(0));
}
bool has_a = image.matte();
yuv_image image_out = create_yuv_image_444(
static_cast<uint32_t>(image.columns()),
static_cast<uint32_t>(image.rows()),
has[channel::Y],
has[channel::U],
has[channel::V],
has_a);
// Create pixels with default values.
// Note that this hides the lack of planes.
rgb_color rgb;
yuv_color yuv;
const Magick::PixelPacket *pixels = image.getConstPixels(0, 0, image.columns(), image.rows());
for (uint32_t y = 0; y < image_out.image_h; y++) {
for (uint32_t x = 0; x < image_out.image_w; x++) {
// Fetch color from ImageMagick
const Magick::ColorRGB magick_rgb = Magick::Color(pixels[y * image.columns() + x]);
rgb.r = static_cast<float>(magick_rgb.red());
rgb.g = static_cast<float>(magick_rgb.green());
rgb.b = static_cast<float>(magick_rgb.blue());
// Imagemagick stores alpha as 0.0 = opaque
rgb.a = static_cast<float>(1.0-magick_rgb.alpha());
// Convert to yuv.
to_yuv(&yuv, rgb, conversion_matrix);
// Assign pixel
set_yuv_color(image_out, yuv, x, y);
}
}
// No syncing needed.
return image_out;
}
/** \brief Normalize the loaded image.(set all least significant bits of all RGB-Values to 0).
* This change takes effect only while editing the picture. In the exported image, all pixel have their old value (except the edited ones).
* This is needed to differentiate between edited and not edited pixel.
*/
void SteganoHide::normalizeImage() {
for(unsigned int xValue = 0; xValue < this->xResolution; xValue++) {
for(unsigned int yValue = 0; yValue < this->yResolution; yValue++) {
Magick::ColorRGB curPixelColor = this->steganoImage.pixelColor(xValue, yValue);
RGB curPixelRGB(convert16BitTo8BitRGB(curPixelColor.redQuantum()),
convert16BitTo8BitRGB(curPixelColor.greenQuantum()),
convert16BitTo8BitRGB(curPixelColor.blueQuantum()));
RGB curPixelRoundedRGB(curPixelRGB.red - (curPixelRGB.red % 10) + 5,
curPixelRGB.green - (curPixelRGB.green % 10) + 5,
curPixelRGB.blue - (curPixelRGB.blue % 10) + 5);
this->steganoImage.pixelColor(xValue, yValue, Magick::ColorRGB(curPixelRoundedRGB.toString()));
}
this->doneBytes += this->yResolution;
}
}
//Konverterer et QImage til Magick::Image
void image_wrapper::to_Image(QImage& qimage)
{
img_ptr_current = new Magick::Image(Magick::Geometry(qimage.width(), qimage.height()), Magick::ColorRGB(0.5, 0.2, 0.3));
double scale = 1 / 256.0;
img_ptr_current->modifyImage();
Magick::PixelPacket *pixels;
Magick::ColorRGB mgc;
for (int y = 0; y < qimage.height(); y++) {
pixels = img_ptr_current->setPixels(0, y, img_ptr_current->columns(), 1);
for (int x = 0; x < qimage.width(); x++) {
QColor pix = qimage.pixel(x, y);
mgc.red(scale *pix.red());
mgc.green(scale *pix.green());
mgc.blue(scale *pix.blue());
*pixels++ = mgc;
}
img_ptr_current->syncPixels();
}
}
// TODO: handle wrong input
bool SteganoHide::hideNumberInMagickColorRGB(const unsigned short &smallNumber, Magick::ColorRGB &color) {
RGB pixelRGB(convert16BitTo8BitRGB(color.redQuantum()),
convert16BitTo8BitRGB(color.greenQuantum()),
convert16BitTo8BitRGB(color.blueQuantum()));
RGB roundedRGB;
roundedRGB.red = pixelRGB.red - (pixelRGB.red % 10);
roundedRGB.green = pixelRGB.green - (pixelRGB.green % 10);
roundedRGB.blue = pixelRGB.blue - (pixelRGB.blue % 10);
unsigned char mostSignificantBit = std::floor(smallNumber / 100);
unsigned char middleSigificantBit = std::floor(smallNumber % 100 / 10);
unsigned char leastSignificantBit = smallNumber % 10;
/* if(mostSignificantBit > 5 || middleSigificantBit > 5 || leastSignificantBit > 5) {
throw hideNumber2Big;
}*/
// there was an overflow: eg. roundedRGB.blue = 250 and leastSignificantLetterBit = 8 => 258 => 2
// This way to check overflow is possible, because *SignificantLetterBit >= 0
if(roundedRGB.green + middleSigificantBit > 255) {
return false;
}
if(roundedRGB.blue + leastSignificantBit > 255) {
return false;
}
// std::cout << (int)roundedRGB.blue << "+" << (int)leastSignificantBit << "=";
roundedRGB.red += mostSignificantBit;
roundedRGB.green += middleSigificantBit;
roundedRGB.blue += leastSignificantBit;
//std::cout << (int)roundedRGB.blue << std::endl;
color = Magick::ColorRGB(roundedRGB.toString());
return true;
}
// TODO: shorten this method and outsource some inner methods and add header comment
std::stringstream SteganoExpose::unhidePhrase(const std::string &password)
{
if(!this->steganoImage.isValid())
{
throw SteganoException::UnhideFileNotSpecified();
}
this->exposeFinished = false;
Chunk hiddenChunk("vaPh");
std::cout << this->steganoImage.baseFilename() << std::endl;
PrivateChunk privChunk(this->steganoImage.baseFilename(), "./omg.png");
char *chunkData = new char[privChunk.getChunkSize(hiddenChunk)];
privChunk.readChunk(hiddenChunk, chunkData);
commentReaderStream.str(chunkData);
calculateNextShift();
Pixel curPixel(0, 0);
std::stringstream returnPhrase;
for(unsigned int runCounter = 0; ; runCounter++)
{
curPixel.x = 0;
curPixel.y = 0;
int_least64_t steps = quadraticSondation(runCounter, this->xResolution * this->yResolution);
// std::cout << "Push by" << steps << std::endl;
pushPixelBy(curPixel, steps);
// std::cout << curPixel.x << ":" << curPixel.y << std::endl;
if(runCounter == shiftIndex)
{
pushPixelBy(curPixel, shiftAmount);
calculateNextShift();
}
// std::cout << curPixel.x << "::" << curPixel.y << std::endl;
Magick::ColorRGB curPixelColor = this->steganoImage.pixelColor(curPixel.x, curPixel.y);
unsigned char redLeastSignificantBit = convert16BitTo8BitRGB(curPixelColor.redQuantum()) % 10;
unsigned char greenLeastSignificantBit = convert16BitTo8BitRGB(curPixelColor.greenQuantum()) % 10;
unsigned char blueLeastSignificantBit = convert16BitTo8BitRGB(curPixelColor.blueQuantum()) % 10;
// there was an overflow at the pixel color. we need to handle it special.
unsigned char decryptedChar = 0;
if(redLeastSignificantBit == 4)
{
decryptedChar += greenLeastSignificantBit * 10;
decryptedChar += blueLeastSignificantBit;
incrementPixel(curPixel);
curPixelColor = this->steganoImage.pixelColor(curPixel.x, curPixel.y);
redLeastSignificantBit = convert16BitTo8BitRGB(curPixelColor.redQuantum()) % 10;
greenLeastSignificantBit = convert16BitTo8BitRGB(curPixelColor.greenQuantum()) % 10;
blueLeastSignificantBit = convert16BitTo8BitRGB(curPixelColor.blueQuantum()) % 10;
decryptedChar += redLeastSignificantBit * 100;
decryptedChar += greenLeastSignificantBit * 10;
decryptedChar += blueLeastSignificantBit;
}
else
{
decryptedChar = redLeastSignificantBit * 100;
decryptedChar += greenLeastSignificantBit * 10;
decryptedChar += blueLeastSignificantBit;
}
if(isFinishPixel(curPixel))
{
break;
}
returnPhrase << decryptedChar;
}
this->exposeFinished = true;
return returnPhrase;
}
