diff --git a/retroshare-gui/src/gui/Identity/IdEditDialog.cpp b/retroshare-gui/src/gui/Identity/IdEditDialog.cpp
index 4b5095fb3..ac9965d2a 100644
--- a/retroshare-gui/src/gui/Identity/IdEditDialog.cpp
+++ b/retroshare-gui/src/gui/Identity/IdEditDialog.cpp
@@ -31,9 +31,10 @@
 #include "util/misc.h"
 #include "gui/notifyqt.h"
 
-#include <retroshare/rsidentity.h>
-#include <retroshare/rspeers.h>
+#include "retroshare/rsidentity.h"
+#include "retroshare/rspeers.h"
 #include "gui/common/FilesDefs.h"
+#include "util/imageutil.h"
 
 #include <iostream>
 
@@ -576,8 +577,10 @@ void IdEditDialog::createId()
         QByteArray ba;
         QBuffer buffer(&ba);
 
+        bool has_transparency = ImageUtil::hasAlphaContent(mAvatar.toImage());
+
         buffer.open(QIODevice::WriteOnly);
-        mAvatar.save(&buffer, "PNG"); // writes image into ba in PNG format
+        mAvatar.save(&buffer, has_transparency?"PNG":"JPG"); // writes image into ba in PNG format
 
         params.mImage.copy((uint8_t *) ba.data(), ba.size());
     }
@@ -648,8 +651,10 @@ void IdEditDialog::updateId()
 		QByteArray ba;
 		QBuffer buffer(&ba);
 
-		buffer.open(QIODevice::WriteOnly);
-		mAvatar.save(&buffer, "PNG"); // writes image into ba in PNG format
+        bool has_transparency = ImageUtil::hasAlphaContent(mAvatar.toImage());
+
+        buffer.open(QIODevice::WriteOnly);
+        mAvatar.save(&buffer, has_transparency?"PNG":"JPG"); // writes image into ba in PNG format
 
 		mEditGroup.mImage.copy((uint8_t *) ba.data(), ba.size());
 	}
diff --git a/retroshare-gui/src/gui/PhotoShare/AlbumItem.cpp b/retroshare-gui/src/gui/PhotoShare/AlbumItem.cpp
index a28b500e5..fea04adbc 100644
--- a/retroshare-gui/src/gui/PhotoShare/AlbumItem.cpp
+++ b/retroshare-gui/src/gui/PhotoShare/AlbumItem.cpp
@@ -47,7 +47,7 @@ void AlbumItem::setUp()
     if(mAlbum.mThumbnail.mSize != 0)
     {
         QPixmap qtn;
-        qtn.loadFromData(mAlbum.mThumbnail.mData, mAlbum.mThumbnail.mSize, "PNG");
+        qtn.loadFromData(mAlbum.mThumbnail.mData, mAlbum.mThumbnail.mSize, "JPG");
         ui->label_Thumbnail->setPixmap(qtn);
     }
     else
diff --git a/retroshare-gui/src/gui/Posted/BoardPostDisplayWidget.cpp b/retroshare-gui/src/gui/Posted/BoardPostDisplayWidget.cpp
index da47d7596..8209b5d1b 100644
--- a/retroshare-gui/src/gui/Posted/BoardPostDisplayWidget.cpp
+++ b/retroshare-gui/src/gui/Posted/BoardPostDisplayWidget.cpp
@@ -330,7 +330,7 @@ void BoardPostDisplayWidget_compact::setup()
 #ifdef DEBUG_BOARDPOSTDISPLAYWIDGET
             std::cerr << "Got pixmap of size " << pixmap.width() << " x " << pixmap.height() << std::endl;
             std::cerr << "Saving to pix.png" << std::endl;
-            pixmap.save("pix.png","PNG");
+            pixmap.save("pix.png","JPG");
 #endif
 
             ui->pictureLabel->setPicture(pixmap);
diff --git a/retroshare-gui/src/gui/Posted/PostedCreatePostDialog.cpp b/retroshare-gui/src/gui/Posted/PostedCreatePostDialog.cpp
index c1e0ce5ad..aace423f8 100644
--- a/retroshare-gui/src/gui/Posted/PostedCreatePostDialog.cpp
+++ b/retroshare-gui/src/gui/Posted/PostedCreatePostDialog.cpp
@@ -224,7 +224,7 @@ void PostedCreatePostDialog::addPicture()
 		}
 
 		QImage opt;
-		if(ImageUtil::optimizeSizeBytes(imagebytes, image, opt, 640*480, MAXMESSAGESIZE - 2000)) { //Leave space for other stuff
+        if(ImageUtil::optimizeSizeBytes(imagebytes, image, opt,"JPG", 640*480, MAXMESSAGESIZE - 2000)) { //Leave space for other stuff
 			ui->imageLabel->setPixmap(QPixmap::fromImage(opt));
 			ui->stackedWidgetPicture->setCurrentIndex(IMG_PICTURE);
 			ui->removeButton->show();
diff --git a/retroshare-gui/src/gui/Posted/PostedGroupDialog.cpp b/retroshare-gui/src/gui/Posted/PostedGroupDialog.cpp
index 6414db7cd..f2b011adb 100644
--- a/retroshare-gui/src/gui/Posted/PostedGroupDialog.cpp
+++ b/retroshare-gui/src/gui/Posted/PostedGroupDialog.cpp
@@ -22,8 +22,9 @@
 #include "PostedGroupDialog.h"
 #include "gui/gxs/GxsIdDetails.h"
 #include "gui/common/FilesDefs.h"
+#include "util/imageutil.h"
 
-#include <retroshare/rswiki.h>
+#include "retroshare/rswiki.h"
 #include <iostream>
 
 const uint32_t PostedCreateEnabledFlags = ( 
@@ -104,8 +105,10 @@ void PostedGroupDialog::preparePostedGroup(RsPostedGroup &group, const RsGroupMe
 		QByteArray ba;
 		QBuffer buffer(&ba);
 
-		buffer.open(QIODevice::WriteOnly);
-		pixmap.save(&buffer, "PNG"); // writes image into ba in PNG format
+        bool has_transparency = ImageUtil::hasAlphaContent(pixmap.toImage());
+
+        buffer.open(QIODevice::WriteOnly);
+        pixmap.save(&buffer, has_transparency?"PNG":"JPG"); // writes image into ba in PNG format
 
 		group.mGroupImage.copy((uint8_t *) ba.data(), ba.size());
 	} else {
diff --git a/retroshare-gui/src/gui/TheWire/WireGroupDialog.cpp b/retroshare-gui/src/gui/TheWire/WireGroupDialog.cpp
index 1be0c9a2c..e13cd4f8f 100644
--- a/retroshare-gui/src/gui/TheWire/WireGroupDialog.cpp
+++ b/retroshare-gui/src/gui/TheWire/WireGroupDialog.cpp
@@ -109,7 +109,7 @@ void WireGroupDialog::prepareWireGroup(RsWireGroup &group, const RsGroupMetaData
 		QBuffer buffer(&ba);
 
 		buffer.open(QIODevice::WriteOnly);
-		pixmap.save(&buffer, "PNG"); // writes image into ba in PNG format
+        pixmap.save(&buffer, "PNG"); // writes image into ba in PNG format
 
 		group.mHeadshot.copy((uint8_t *) ba.data(), ba.size());
 	} else {
@@ -126,7 +126,7 @@ void WireGroupDialog::prepareWireGroup(RsWireGroup &group, const RsGroupMetaData
 		QBuffer buffer(&ba);
 
 		buffer.open(QIODevice::WriteOnly);
-		pixmap.save(&buffer, "JPG");
+        pixmap.save(&buffer, "PNG");
 
 		group.mMasthead.copy((uint8_t *) ba.data(), ba.size());
 	} else {
diff --git a/retroshare-gui/src/gui/chat/ChatWidget.cpp b/retroshare-gui/src/gui/chat/ChatWidget.cpp
index ab198fa33..72e2db1d8 100644
--- a/retroshare-gui/src/gui/chat/ChatWidget.cpp
+++ b/retroshare-gui/src/gui/chat/ChatWidget.cpp
@@ -1094,7 +1094,7 @@ void ChatWidget::addChatMsg(bool incoming, const QString &name, const RsGxsId gx
 			QImage image(icon.pixmap(height,height).toImage());
 			QByteArray byteArray;
 			QBuffer buffer(&byteArray);
-			image.save(&buffer, "PNG"); // writes the image in PNG format inside the buffer
+            image.save(&buffer, "PNG"); // writes the image in PNG format inside the buffer
 			QString iconBase64 = QString::fromLatin1(byteArray.toBase64().data());
 			strPreName = QString("<img src=\"data:image/png;base64,%1\" alt=\"[unsigned]\" />").arg(iconBase64);
 		}
@@ -1677,7 +1677,7 @@ void ChatWidget::addExtraPicture()
 	if (misc::getOpenFileName(window(), RshareSettings::LASTDIR_IMAGES, tr("Load Picture File"), "Pictures (*.png *.xpm *.jpg *.jpeg *.gif *.webp )", file)) {
 		QString encodedImage;
 		uint32_t maxMessageSize = this->maxMessageSize();
-		if (RsHtml::makeEmbeddedImage(file, encodedImage, 640*480, maxMessageSize - 200)) {		//-200 for the html stuff
+        if (RsHtml::makeEmbeddedImage(file, encodedImage, 640*480, maxMessageSize - 200)) {		//-200 for the html stuff
 			QTextDocumentFragment fragment = QTextDocumentFragment::fromHtml(encodedImage);
 			ui->chatTextEdit->textCursor().insertFragment(fragment);
 		}
diff --git a/retroshare-gui/src/gui/common/AvatarDialog.cpp b/retroshare-gui/src/gui/common/AvatarDialog.cpp
index 632fa2948..dd302b570 100644
--- a/retroshare-gui/src/gui/common/AvatarDialog.cpp
+++ b/retroshare-gui/src/gui/common/AvatarDialog.cpp
@@ -40,6 +40,7 @@
 #include "util/misc.h"
 #include "gui/common/FilesDefs.h"
 #include "util/HandleRichText.h"
+#include "util/imageutil.h"
 #include "retroshare/rsinit.h"
 
 #define ICONNAME "groupicon.png"
@@ -138,10 +139,11 @@ void AvatarDialog::getAvatar(QByteArray &avatar)
 		return;
 	}
 
-	QBuffer buffer(&avatar);
+    bool has_transparency = ImageUtil::hasAlphaContent(pixmap.toImage());
+    QBuffer buffer(&avatar);
 
 	buffer.open(QIODevice::WriteOnly);
-	pixmap.save(&buffer, "PNG"); // writes image into ba in PNG format
+    pixmap.save(&buffer, has_transparency?"PNG":"JPG"); // writes image into ba in PNG format
 }
 
 void AvatarDialog::load()
diff --git a/retroshare-gui/src/gui/gxschannels/CreateGxsChannelMsg.cpp b/retroshare-gui/src/gui/gxschannels/CreateGxsChannelMsg.cpp
index e8f34d1eb..c834ae3da 100644
--- a/retroshare-gui/src/gui/gxschannels/CreateGxsChannelMsg.cpp
+++ b/retroshare-gui/src/gui/gxschannels/CreateGxsChannelMsg.cpp
@@ -611,7 +611,7 @@ bool CreateGxsChannelMsg::setThumbNail(const std::string& path, int frame){
 	QByteArray ba;
 	QBuffer buffer(&ba);
 	buffer.open(QIODevice::WriteOnly);
-	tNail.save(&buffer, "PNG");
+    tNail.save(&buffer, "JPG");
 	QPixmap img;
 	img.loadFromData(ba, "PNG");
 	img = img.scaled(thumbnail_label->width(), thumbnail_label->height(), Qt::KeepAspectRatio, Qt::SmoothTransformation);
@@ -814,7 +814,7 @@ void CreateGxsChannelMsg::sendMessage(const std::string &subject, const std::str
 			// send chan image
 
 			buffer.open(QIODevice::WriteOnly);
-            preview_W->getCroppedScaledPicture().save(&buffer, "PNG"); // writes image into ba in PNG format
+            preview_W->getCroppedScaledPicture().save(&buffer, "JPG"); // writes image into ba in PNG format
 			post.mThumbnail.copy((uint8_t *) ba.data(), ba.size());
 		}
 
diff --git a/retroshare-gui/src/gui/gxschannels/GxsChannelGroupDialog.cpp b/retroshare-gui/src/gui/gxschannels/GxsChannelGroupDialog.cpp
index a98e9016a..0af2631c5 100644
--- a/retroshare-gui/src/gui/gxschannels/GxsChannelGroupDialog.cpp
+++ b/retroshare-gui/src/gui/gxschannels/GxsChannelGroupDialog.cpp
@@ -21,10 +21,11 @@
 #include <QBuffer>
 
 #include "gui/gxs/GxsIdDetails.h"
+#include "util/imageutil.h"
 #include "gui/common/FilesDefs.h"
 #include "GxsChannelGroupDialog.h"
 
-#include <retroshare/rsgxschannels.h>
+#include "retroshare/rsgxschannels.h"
 #include <iostream>
 
 // To start with we only have open forums - with distribution controls.
@@ -119,8 +120,10 @@ void GxsChannelGroupDialog::prepareChannelGroup(RsGxsChannelGroup &group, const
 		QByteArray ba;
 		QBuffer buffer(&ba);
 
-		buffer.open(QIODevice::WriteOnly);
-		pixmap.save(&buffer, "PNG"); // writes image into ba in PNG format
+        bool has_transparency = ImageUtil::hasAlphaContent(pixmap.toImage());
+
+        buffer.open(QIODevice::WriteOnly);
+        pixmap.save(&buffer, has_transparency?"PNG":"JPG"); // writes image into ba in PNG format
 
 		group.mImage.copy((uint8_t *) ba.data(), ba.size());
 	} else {
diff --git a/retroshare-gui/src/gui/gxschannels/GxsChannelPostThumbnail.cpp b/retroshare-gui/src/gui/gxschannels/GxsChannelPostThumbnail.cpp
index ee40e1465..16cf96195 100644
--- a/retroshare-gui/src/gui/gxschannels/GxsChannelPostThumbnail.cpp
+++ b/retroshare-gui/src/gui/gxschannels/GxsChannelPostThumbnail.cpp
@@ -350,7 +350,7 @@ void ZoomableLabel::updateView()
     std::cerr << "               Image size: " << mFullImage.width() << " x " << mFullImage.height() << ", window size: " << width() << " x " << height() << std::endl;
     std::cerr << "               cropped image: " << rect.left() << "," << rect.top() << "+" << rect.width() << "+" << rect.height() << std::endl;
     std::cerr << "               saving crop to pix2.png" << std::endl;
-    mFullImage.copy(rect).save("pix2.png","PNG");
+    mFullImage.copy(rect).save("pix2.png","JPG");
 #endif
     QLabel::setPixmap(mFullImage.copy(rect));
 }
diff --git a/retroshare-gui/src/gui/gxschannels/GxsChannelPostsWidgetWithModel.cpp b/retroshare-gui/src/gui/gxschannels/GxsChannelPostsWidgetWithModel.cpp
index fbf09350a..1d8de3f89 100644
--- a/retroshare-gui/src/gui/gxschannels/GxsChannelPostsWidgetWithModel.cpp
+++ b/retroshare-gui/src/gui/gxschannels/GxsChannelPostsWidgetWithModel.cpp
@@ -164,7 +164,7 @@ void ChannelPostDelegate::paint(QPainter * painter, const QStyleOptionViewItem &
 //        {
 //            QFile file("yourFile.png");
 //            file.open(QIODevice::WriteOnly);
-//            pixmap.save(&file, "PNG");
+//            pixmap.save(&file, "JPG");
 //            file.close();
 //        }
 
diff --git a/retroshare-gui/src/gui/gxsforums/GxsForumModel.cpp b/retroshare-gui/src/gui/gxsforums/GxsForumModel.cpp
index 07d44ca1b..77292dadf 100644
--- a/retroshare-gui/src/gui/gxsforums/GxsForumModel.cpp
+++ b/retroshare-gui/src/gui/gxsforums/GxsForumModel.cpp
@@ -566,7 +566,7 @@ QVariant RsGxsForumModel::toolTipRole(const ForumModelPostEntry& fmpe,int column
 		QImage pix( (*icons.begin()).pixmap(QSize(5*S,5*S)).toImage());
 
 		QString embeddedImage;
-		if(RsHtml::makeEmbeddedImage(pix.scaled(QSize(5*S,5*S), Qt::KeepAspectRatio, Qt::SmoothTransformation), embeddedImage, -1))
+        if(RsHtml::makeEmbeddedImage(pix.scaled(QSize(5*S,5*S), Qt::KeepAspectRatio, Qt::SmoothTransformation), embeddedImage, -1))
 		{
 			embeddedImage.insert(embeddedImage.indexOf("src="), "style=\"float:left\" ");
 			comment = "<table><tr><td>" + embeddedImage + "</td><td>" + comment + "</td></table>";
diff --git a/retroshare-gui/src/util/HandleRichText.cpp b/retroshare-gui/src/util/HandleRichText.cpp
index bba7c03af..6f6eec750 100644
--- a/retroshare-gui/src/util/HandleRichText.cpp
+++ b/retroshare-gui/src/util/HandleRichText.cpp
@@ -1216,7 +1216,7 @@ bool RsHtml::makeEmbeddedImage(const QString &fileName, QString &embeddedImage,
 		fprintf (stderr, "RsHtml::makeEmbeddedImage() - image \"%s\" can't be load\n", fileName.toLatin1().constData());
 		return false;
 	}
-	return RsHtml::makeEmbeddedImage(image, embeddedImage, maxPixels, maxBytes);
+    return RsHtml::makeEmbeddedImage(image, embeddedImage, maxPixels, maxBytes);
 }
 
 /** Converts image to embedded image HTML fragment **/
@@ -1224,7 +1224,7 @@ bool RsHtml::makeEmbeddedImage(const QImage &originalImage, QString &embeddedIma
 {
 	rstime::RsScopeTimer s("Embed image");
 	QImage opt;
-	return ImageUtil::optimizeSizeHtml(embeddedImage, originalImage, opt, maxPixels, maxBytes);
+    return ImageUtil::optimizeSizeHtml(embeddedImage, originalImage, opt, maxPixels, maxBytes);
 }
 
 QString RsHtml::plainText(const QString &text)
diff --git a/retroshare-gui/src/util/HandleRichText.h b/retroshare-gui/src/util/HandleRichText.h
index 9462ba865..3e98ea21c 100644
--- a/retroshare-gui/src/util/HandleRichText.h
+++ b/retroshare-gui/src/util/HandleRichText.h
@@ -70,7 +70,7 @@ public:
 	static QString toHtml(QString text, bool realHtml = true);
 
 	static bool    makeEmbeddedImage(const QString &fileName, QString &embeddedImage, const int maxPixels, const int maxBytes = -1);
-	static bool    makeEmbeddedImage(const QImage &originalImage, QString &embeddedImage, const int maxPixels, const int maxBytes = -1);
+    static bool    makeEmbeddedImage(const QImage &originalImage, QString &embeddedImage, const int maxPixels, const int maxBytes = -1);
 
 	static QString plainText(const QString &text);
 	static QString plainText(const std::string &text);
diff --git a/retroshare-gui/src/util/imageutil.cpp b/retroshare-gui/src/util/imageutil.cpp
index 47029505e..d710a9ae3 100644
--- a/retroshare-gui/src/util/imageutil.cpp
+++ b/retroshare-gui/src/util/imageutil.cpp
@@ -68,12 +68,12 @@ void ImageUtil::extractImage(QWidget *window, QTextCursor cursor, QString file)
 	}
 }
 
-bool ImageUtil::optimizeSizeBytes(QByteArray &bytearray, const QImage &original, QImage &optimized, int maxPixels, int maxBytes)
+bool ImageUtil::optimizeSizeBytes(QByteArray &bytearray, const QImage &original, QImage &optimized, const char *format, int maxPixels, int maxBytes)
 {
 	//nothing to do if it fits into the limits
 	optimized = original;
 	if ((maxPixels <= 0) || (optimized.width()*optimized.height() <= maxPixels)) {
-		int s = checkSize(bytearray, optimized);
+        int s = checkSize(bytearray, optimized,format);
 		if((maxBytes <= 0) || (s <= maxBytes)) {
 			return true;
 		}
@@ -92,7 +92,7 @@ bool ImageUtil::optimizeSizeBytes(QByteArray &bytearray, const QImage &original,
 
 	//if maxBytes not defined, do not reduce color space, just downscale
 	if(maxBytes <= 0) {
-		checkSize(bytearray, optimized = original.scaledToWidth(maxwidth, Qt::SmoothTransformation));
+        checkSize(bytearray, optimized = original.scaledToWidth(maxwidth, Qt::SmoothTransformation),format);
 		return true;
 	}
 
@@ -100,9 +100,9 @@ bool ImageUtil::optimizeSizeBytes(QByteArray &bytearray, const QImage &original,
 	quantization(original, ct);
 
 	//Use binary search to find a suitable image size + linear regression to guess the file size
-	double maxsize = (double)checkSize(bytearray, optimized = original.scaledToWidth(maxwidth, Qt::SmoothTransformation).convertToFormat(QImage::Format_Indexed8, ct, Qt::ThresholdDither));
+    double maxsize = (double)checkSize(bytearray, optimized = original.scaledToWidth(maxwidth, Qt::SmoothTransformation).convertToFormat(QImage::Format_Indexed8, ct, Qt::ThresholdDither),format);
 	if(maxsize <= maxBytes) return true;	//success
-	double minsize = (double)checkSize(bytearray, optimized = original.scaledToWidth(minwidth, Qt::SmoothTransformation).convertToFormat(QImage::Format_Indexed8, ct, Qt::ThresholdDither));
+    double minsize = (double)checkSize(bytearray, optimized = original.scaledToWidth(minwidth, Qt::SmoothTransformation).convertToFormat(QImage::Format_Indexed8, ct, Qt::ThresholdDither),format);
 	if(minsize > maxBytes) return false; //impossible
 
 //	std::cout << "maxS: " << maxsize << " minS: " << minsize << std::endl;
@@ -115,7 +115,7 @@ bool ImageUtil::optimizeSizeBytes(QByteArray &bytearray, const QImage &original,
 		double b = maxsize - m * ((double)maxwidth * (double)maxwidth / whratio);
 		double a = ((double)(maxBytes - region/2) - b) / m; //maxBytes - region/2 target the center of the accepted region
 		int nextwidth = (int)sqrt(a * whratio);
-		int nextsize = checkSize(bytearray, optimized = original.scaledToWidth(nextwidth, Qt::SmoothTransformation).convertToFormat(QImage::Format_Indexed8, ct, Qt::ThresholdDither));
+        int nextsize = checkSize(bytearray, optimized = original.scaledToWidth(nextwidth, Qt::SmoothTransformation).convertToFormat(QImage::Format_Indexed8, ct, Qt::ThresholdDither),format);
 		if(nextsize <= maxBytes) {
 			minsize = nextsize;
 			minwidth = nextwidth;
@@ -137,6 +137,25 @@ bool ImageUtil::optimizeSizeBytes(QByteArray &bytearray, const QImage &original,
 	//std::cout << html.toStdString() << std::endl;
 }
 
+bool ImageUtil::hasAlphaContent(const QImage& image)
+{
+    if(!image.hasAlphaChannel())
+    {
+        std::cerr << "Image of size " << image.width() << " x " << image.height() << ": No transparency content detected." << std::endl;
+        return false;
+    }
+
+    for(int i=0;i<image.width();++i)
+        for(int j=0;j<image.height();++j)
+            if(qAlpha(image.pixel(i,j)) < 255)
+            {
+                std::cerr << "Image of size " << image.width() << " x " << image.height() << ": Transparency content detected." << std::endl;
+                return true;
+            }
+
+    std::cerr << "Image of size " << image.width() << " x " << image.height() << ": No transparency content detected." << std::endl;
+    return false;
+}
 bool ImageUtil::optimizeSizeHtml(QString &html, const QImage& original, QImage &optimized, int maxPixels, int maxBytes)
 {
 	QByteArray bytearray;
@@ -145,7 +164,10 @@ bool ImageUtil::optimizeSizeHtml(QString &html, const QImage& original, QImage &
 		if(maxBytes < 1) maxBytes = 1;
 	}
 
-	if(optimizeSizeBytes(bytearray, original, optimized, maxPixels, maxBytes))
+    // check for transparency
+    bool has_transparency = hasAlphaContent(original);
+
+    if(optimizeSizeBytes(bytearray, original, optimized,has_transparency?"PNG":"JPG",maxPixels, maxBytes))
 	{
 		QByteArray encodedByteArray = bytearray.toBase64();
 		html = "<img src=\"data:image/png;base64,";
@@ -156,7 +178,7 @@ bool ImageUtil::optimizeSizeHtml(QString &html, const QImage& original, QImage &
 	return false;
 }
 
-int ImageUtil::checkSize(QByteArray &bytearray, const QImage &img)
+int ImageUtil::checkSize(QByteArray &bytearray, const QImage &img,const char *format)
 {
 	rstime::RsScopeTimer st("Check size");
 
@@ -166,7 +188,7 @@ int ImageUtil::checkSize(QByteArray &bytearray, const QImage &img)
 
 	//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)) {
+        if (img.save(&buffer, format, 85)) {
 			size = bytearray.length();
 		} else {
 			std::cerr << "ImageUtil: image can't be saved to buffer" << std::endl;
diff --git a/retroshare-gui/src/util/imageutil.h b/retroshare-gui/src/util/imageutil.h
index 1a9658e13..9e5bf37cb 100644
--- a/retroshare-gui/src/util/imageutil.h
+++ b/retroshare-gui/src/util/imageutil.h
@@ -32,11 +32,12 @@ public:
 	ImageUtil();
 
 	static void extractImage(QWidget *window, QTextCursor cursor, QString file = "");
-	static bool optimizeSizeHtml(QString &html, const QImage& original, QImage &optimized, int maxPixels = -1, int maxBytes = -1);
-	static bool optimizeSizeBytes(QByteArray &bytearray, const QImage& original, QImage &optimized, int maxPixels = -1, int maxBytes = -1);
+    static bool optimizeSizeHtml(QString &html, const QImage& original, QImage &optimized, int maxPixels = -1, int maxBytes = -1);
+    static bool optimizeSizeBytes(QByteArray &bytearray, const QImage &original, QImage &optimized, const char *format, int maxPixels, int maxBytes);
+    static bool hasAlphaContent(const QImage& image);
 
 	private:
-		static int checkSize(QByteArray& embeddedImage, const QImage& img);
+        static int checkSize(QByteArray& embeddedImage, const QImage& img, const char *format);
 		static void quantization(const QImage& img, QVector<QRgb>& palette);
 		static void quantization(QList<QRgb>::iterator begin, QList<QRgb>::iterator end, int depth, QVector<QRgb>& palette);
 		static void avgbucket(QList<QRgb>::iterator begin, QList<QRgb>::iterator end, QVector<QRgb>& palette);
diff --git a/retroshare-gui/src/util/misc.cpp b/retroshare-gui/src/util/misc.cpp
index 2f6337d1b..84c408de3 100644
--- a/retroshare-gui/src/util/misc.cpp
+++ b/retroshare-gui/src/util/misc.cpp
@@ -291,7 +291,7 @@ bool misc::getOpenAvatarPicture(QWidget *parent, QByteArray &image_data)
 	// save image in QByteArray
 	QBuffer buffer(&image_data);
 	buffer.open(QIODevice::WriteOnly);
-	picture.save(&buffer, "PNG"); // writes image into ba in PNG format
+    picture.save(&buffer, "PNG"); // writes image into ba in PNG format
 
 	return true;
 }