imagewidget.cpp

/*
 * Copyright (C) 2012 Jorge Aparicio <jorge.aparicio.r@gmail.com>
 *
 * This file is part of qSerialTerm.
 *
 * qSerialTerm is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * any later version.

 * qSerialTerm is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with qSerialTerm.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "imagewidget.h"
#include "ui_imagewidget.h"

ImageWidget::ImageWidget(QWidget *parent) :
  QWidget(parent),
  ui(new Ui::ImageWidget),
  image(0)
{
  ui->setupUi(this);

  ui->formatComboBox->addItem("Monochrome", MONO);
  ui->formatComboBox->addItem("RGB888", RGB888);
  ui->formatComboBox->addItem("YCbCr422", YCBCR422);
}

ImageWidget::~ImageWidget()
{
  delete ui;
}

void ImageWidget::display(QByteArray incomingData)
{
  static QByteArray storedData;

  if (image) {
    int width = image->width();
    int height = image->height();
    int numberOfBytes = width * height;

    switch (ui->formatComboBox->itemData(ui->formatComboBox->currentIndex()).value<int>()) {
      case RGB888:
        numberOfBytes *= 3;
        break;
      case YCBCR422:
        numberOfBytes *= 2;
        break;
    }

    storedData.append(incomingData);

    if (storedData.size() >= numberOfBytes) {
      int framesToSkip = storedData.size() / numberOfBytes - 1;

      if (framesToSkip > 0)
        storedData.remove(0, numberOfBytes * framesToSkip);

      QVector<QRgb> pixels = decode(storedData.left(numberOfBytes));

      storedData.remove(0, numberOfBytes);

      for (int j = 0; j < height; j++)
        for (int i = 0; i < width; i++)
          image->setPixel(i, j, pixels.at(j * width + i));

      on_fitToScreenCheckBox_toggled(ui->fitToScreenCheckBox->isChecked());
    }
  }
}

void ImageWidget::on_clearPushButton_clicked()
{
  if (image) {
    for (int j = 0; j < image->height(); j++)
      for (int i = 0; i < image->width(); i++)
        image->setPixel(i, j, qRgb(0, 0, 0));

    on_fitToScreenCheckBox_toggled(ui->fitToScreenCheckBox->isChecked());
  }
}

void ImageWidget::on_startPushButton_clicked()
{
  if (image) {
    ui->imageLabel->setText("Your image goes here.");

    ui->widthSpinBox->setEnabled(true);
    ui->heightSpinBox->setEnabled(true);
    ui->formatComboBox->setEnabled(true);

    ui->startPushButton->setText("Start");

    delete image;
    image = 0;
  } else {
    image = new QImage(ui->widthSpinBox->value(),
                       ui->heightSpinBox->value(),
                       QImage::Format_RGB888);

    ui->widthSpinBox->setDisabled(true);
    ui->heightSpinBox->setDisabled(true);
    ui->formatComboBox->setDisabled(true);

    ui->startPushButton->setText("Stop");

    on_clearPushButton_clicked();
  }
}

void ImageWidget::on_fitToScreenCheckBox_toggled(bool checked)
{
  if (image) {
    ui->imageLabel->clear();

    if (checked)
      ui->imageLabel->setPixmap(QPixmap::fromImage(*image).scaled(ui->imageLabel->size(),
                                                                  Qt::KeepAspectRatio));
    else
      ui->imageLabel->setPixmap(QPixmap::fromImage(*image));
  }
}

QVector<QRgb> ImageWidget::decode(QByteArray data)
{
  QVector<QRgb> pixels;

  switch(ui->formatComboBox->itemData(ui->formatComboBox->currentIndex()).value<int>()) {
    case MONO:
      for (int i = 0; i < data.size(); i++) {
        int level = quint8(data.at(i));
        pixels.append(qRgb(level, level, level));
      }
      break;

    case RGB888:
      for (int i = 0; i < data.size(); i += 3) {
        int red = quint8(data.at(i));
        int green = quint8(data.at(i + 1));
        int blue = quint8(data.at(i + 2));

        pixels.append(qRgb(red, green, blue));
      }
      break;

    case YCBCR422:
      for (int i = 0; i < data.size(); i += 4) {
        int cb = quint8(data.at(i)) - 128;
        int y1 = quint8(data.at(i + 1));
        int cr = quint8(data.at(i + 2)) - 128;
        int y2 = quint8(data.at(i + 3));

        int red = y1 + 1.4 * cr;
        int green = y1 - .343 * cb - .711 * cr;
        int blue = y1 + 1.765 * cb;

        if (red < 0)
          red = 0;
        else if (red > 255)
          red = 255;

        if (green < 0)
          green = 0;
        else if (green > 255)
          green = 255;

        if (blue < 0)
          blue = 0;
        else if (blue > 255)
          blue = 255;

        pixels.append(qRgb(red, green, blue));

        red = y2 + 1.4 * cr;
        green = y2 - .343 * cb - .711 * cr;
        blue = y2 + 1.765 * cb;

        if (red < 0)
          red = 0;
        else if (red > 255)
          red = 255;

        if (green < 0)
          green = 0;
        else if (green > 255)
          green = 255;

        if (blue < 0)
          blue = 0;
        else if (blue > 255)
          blue = 255;

        pixels.append(qRgb(red, green, blue));
      }
      break;
  }

  return pixels;
}