Downscale image automatically

This commit is contained in:
hunbernd 2017-06-08 23:00:33 +02:00
parent f50351063d
commit 9af2730879
3 changed files with 88 additions and 42 deletions

View File

@ -35,6 +35,8 @@
#include "HandleRichText.h"
#include "gui/RetroShareLink.h"
#include "util/ObjectPainter.h"
#include "util/imageutil.h"
#include "util/rsscopetimer.h"
#include <iostream>
@ -1119,48 +1121,9 @@ bool RsHtml::makeEmbeddedImage(const QString &fileName, QString &embeddedImage,
/** Converts image to embedded image HTML fragment **/
bool RsHtml::makeEmbeddedImage(const QImage &originalImage, QString &embeddedImage, const int maxPixels)
{
QByteArray bytearray;
QBuffer buffer(&bytearray);
QImage resizedImage;
const QImage *image = &originalImage;
if (maxPixels > 0) {
QSize imgSize = originalImage.size();
if ((imgSize.height() * imgSize.width()) > maxPixels) {
// image is too large - resize keeping aspect ratio
QSize newSize;
newSize.setWidth(int(qSqrt((maxPixels * imgSize.width()) / imgSize.height())));
newSize.setHeight(int((imgSize.height() * newSize.width()) / imgSize.width()));
// ask user
QMessageBox msgBox;
msgBox.setText(QString(QApplication::translate("RsHtml", "Image is oversized for transmission.\nReducing image to %1x%2 pixels?")).arg(newSize.width()).arg(newSize.height()));
msgBox.setStandardButtons(QMessageBox::Ok | QMessageBox::Cancel);
msgBox.setDefaultButton(QMessageBox::Ok);
if (msgBox.exec() != QMessageBox::Ok) {
return false;
}
resizedImage = originalImage.scaled(newSize, Qt::KeepAspectRatio, Qt::SmoothTransformation);
image = &resizedImage;
}
}
if (buffer.open(QIODevice::WriteOnly)) {
if (image->save(&buffer, "PNG")) {
QByteArray encodedByteArray = bytearray.toBase64();
embeddedImage = "<img src=\"data:image/png;base64,";
embeddedImage.append(encodedByteArray);
embeddedImage.append("\">");
} else {
//fprintf (stderr, "RsHtml::makeEmbeddedImage() - image can't be saved to buffer\n");
return false;
}
} else {
fprintf (stderr, "RsHtml::makeEmbeddedImage() - buffer can't be opened\n");
return false;
}
return true;
RsScopeTimer s("Embed image");
QImage opt;
ImageUtil::optimizeSize(embeddedImage, originalImage, opt, maxPixels, 6000);
}
QString RsHtml::plainText(const QString &text)

View File

@ -8,6 +8,10 @@
#include <QString>
#include <QTextCursor>
#include <QTextDocumentFragment>
#include <QBuffer>
#include <QtGlobal>
#include <QtMath>
#include <iostream>
ImageUtil::ImageUtil() {}
@ -42,3 +46,78 @@ void ImageUtil::extractImage(QWidget *window, QTextCursor cursor)
}
}
void ImageUtil::optimizeSize(QString &html, const QImage& original, QImage &optimized, int maxPixels, int maxBytes)
{
optimized = original;
if ((maxPixels <= 0) || (optimized.width()*optimized.height() <= maxPixels)) {
if(checkSize(html, optimized, maxBytes)) {
return;
}
}
//Downscale the image to fit into maxPixels
qreal scale = qSqrt((qreal)(maxPixels) / original.width() / original.height());
if(scale > 1.0) scale = 1.0;
//Half the resolution until image fits into maxBytes, or width becomes 0
do {
optimized = original.scaledToWidth((int)(original.width() * scale), Qt::SmoothTransformation).convertToFormat(QImage::Format_Indexed8);
checkSize(html, optimized, maxBytes);
scale = scale / 2.0;
} while((!optimized.isNull()) && (!checkSize(html, optimized, maxBytes)));
}
bool ImageUtil::checkSize(QString &embeddedImage, const QImage &img, int maxBytes)
{
QByteArray bytearray;
QBuffer buffer(&bytearray);
std::cout << QString("Trying image: format PNG, size %1x%2, colors %3\n").arg(img.width()).arg(img.height()).arg(img.colorCount()).toStdString();
if (buffer.open(QIODevice::WriteOnly)) {
if (img.save(&buffer, "PNG", 0)) {
QByteArray encodedByteArray = bytearray.toBase64();
embeddedImage = "<img src=\"data:image/png;base64,";
embeddedImage.append(encodedByteArray);
embeddedImage.append("\">");
if((maxBytes > 0) && (embeddedImage.size() > maxBytes))
{
std::cout << QString("\tToo large, size: %1, limit: %2 bytes\n").arg(embeddedImage.size()).arg(maxBytes).toStdString();
}else{
std::cout << QString("\tOK, size: %1, limit: %2 bytes\n").arg(embeddedImage.size()).arg(maxBytes).toStdString();
return true;
}
} else {
std::cerr << "ImageUtil: image can't be saved to buffer" << std::endl;
}
buffer.close();
bytearray.clear();
} else {
std::cerr << "ImageUtil: buffer can't be opened" << std::endl;
}
std::cout << QString("Trying image: format JPEG, size %1x%2, colors %3\n").arg(img.width()).arg(img.height()).arg(img.colorCount()).toStdString();
if (buffer.open(QIODevice::WriteOnly)) {
if (img.save(&buffer, "JPEG")) {
QByteArray encodedByteArray = bytearray.toBase64();
embeddedImage = "<img src=\"data:image/jpeg;base64,";
embeddedImage.append(encodedByteArray);
embeddedImage.append("\">");
if((maxBytes > 0) && (embeddedImage.size() > maxBytes))
{
std::cout << QString("\tToo large, size: %1, limit: %2 bytes\n").arg(embeddedImage.size()).arg(maxBytes).toStdString();
}else{
std::cout << QString("\tOK, size: %1, limit: %2 bytes\n").arg(embeddedImage.size()).arg(maxBytes).toStdString();
return true;
}
} else {
std::cerr << "ImageUtil: image can't be saved to buffer" << std::endl;
}
buffer.close();
bytearray.clear();
} else {
std::cerr << "ImageUtil: buffer can't be opened" << std::endl;
}
embeddedImage.clear();
return false;
}

View File

@ -10,6 +10,10 @@ public:
ImageUtil();
static void extractImage(QWidget *window, QTextCursor cursor);
static void optimizeSize(QString &html, const QImage& original, QImage &optimized, int maxPixels = -1, int maxBytes = -1);
private:
static bool checkSize(QString& embeddedImage, const QImage& img, int maxBytes = -1);
};
#endif // IMAGEUTIL_H