[Digikam-devel] branches/stable/extragear/graphics/digikam/kioslave

[Gilles Caulier]

SVN commit 527172 by cgilles:

digikam from stable: backport Marcel patch from trunk :

Allow reading JPEG files in CMYK color spaces
The image data will be converted to RGB 
in the most simple way as Qt does it.
(For full colorspace independence, use Krita.)

This commit fix thumbnail ioslave only, not image editor that use imlib2 for that.

CCMAIL: digikam-devel at kde.org

 M  +72 -29    digikamthumbnail.cpp  


--- branches/stable/extragear/graphics/digikam/kioslave/digikamthumbnail.cpp #527171:527172
@@ -449,8 +449,7 @@
 {
     static void myjpeg_error_exit(j_common_ptr cinfo)
     {
-        myjpeg_error_mgr* myerr =
-            (myjpeg_error_mgr*) cinfo->err;
+        myjpeg_error_mgr* myerr = (myjpeg_error_mgr*) cinfo->err;
 
         char buffer[JMSG_LENGTH_MAX];
         (*cinfo->err->format_message)(cinfo, buffer);
@@ -461,21 +460,22 @@
 
 bool kio_digikamthumbnailProtocol::loadJPEG(QImage& image, const QString& path)
 {
-    QString format=QImageIO::imageFormat(path);
+    QString format = QImageIO::imageFormat(path);
     if (format !="JPEG") return false;
 
     FILE* inputFile=fopen(QFile::encodeName(path), "rb");
     if(!inputFile)
         return false;
 
-    struct jpeg_decompress_struct    cinfo;
-    struct myjpeg_error_mgr jerr;
+    struct jpeg_decompress_struct cinfo;
+    struct myjpeg_error_mgr       jerr;
 
     // JPEG error handling - thanks to Marcus Meissner
     cinfo.err             = jpeg_std_error(&jerr);
     cinfo.err->error_exit = myjpeg_error_exit;
 
-    if (setjmp(jerr.setjmp_buffer)) {
+    if (setjmp(jerr.setjmp_buffer)) 
+    {
         jpeg_destroy_decompress(&cinfo);
         fclose(inputFile);
         return false;
@@ -488,7 +488,8 @@
     int imgSize = QMAX(cinfo.image_width, cinfo.image_height);
 
     int scale=1;
-    while(cachedSize_*scale*2<=imgSize) {
+    while(cachedSize_*scale*2<=imgSize) 
+    {
         scale*=2;
     }
     if(scale>8) scale=8;
@@ -496,45 +497,87 @@
     cinfo.scale_num=1;
     cinfo.scale_denom=scale;
 
-    // Create QImage
+    switch (cinfo.jpeg_color_space)
+    {
+        case JCS_UNKNOWN:
+            break;
+        case JCS_GRAYSCALE:
+        case JCS_RGB:
+        case JCS_YCbCr:
+            cinfo.out_color_space = JCS_RGB;
+            break;
+        case JCS_CMYK:
+        case JCS_YCCK:
+            cinfo.out_color_space = JCS_CMYK;
+            break;
+    }
+
     jpeg_start_decompress(&cinfo);
 
     QImage img;
 
-    switch(cinfo.output_components) {
-    case 3:
-    case 4:
-        img.create( cinfo.output_width, cinfo.output_height, 32 );
-        break;
-    case 1: // B&W image
-        img.create( cinfo.output_width, cinfo.output_height,
-                    8, 256 );
-        for (int i=0; i<256; i++)
-            img.setColor(i, qRgb(i,i,i));
-        break;
-    default:
+    // We only take RGB with 1 or 3 components, or CMYK with 4 components
+    if (!(
+           (cinfo.out_color_space == JCS_RGB  && (cinfo.output_components == 3 || cinfo.output_components == 1))
+        || (cinfo.out_color_space == JCS_CMYK &&  cinfo.output_components == 4)
+        ))
+    {
+        jpeg_destroy_decompress(&cinfo);
+        fclose(inputFile);
         return false;
     }
 
+    switch(cinfo.output_components) 
+    {
+        case 3:
+        case 4:
+            img.create( cinfo.output_width, cinfo.output_height, 32 );
+            break;
+        case 1: // B&W image
+            img.create( cinfo.output_width, cinfo.output_height, 8, 256 );
+            for (int i = 0 ; i < 256 ; i++)
+                img.setColor(i, qRgb(i, i, i));
+            break;
+    }
+
     uchar** lines = img.jumpTable();
     while (cinfo.output_scanline < cinfo.output_height)
-        jpeg_read_scanlines(&cinfo, lines + cinfo.output_scanline,
-                            cinfo.output_height);
+        jpeg_read_scanlines(&cinfo, lines + cinfo.output_scanline, cinfo.output_height);
+        
     jpeg_finish_decompress(&cinfo);
 
     // Expand 24->32 bpp
-    if ( cinfo.output_components == 3 ) {
-        for (uint j=0; j<cinfo.output_height; j++) {
+    if ( cinfo.output_components == 3 )
+    {
+        for (uint j=0; j<cinfo.output_height; j++) 
+        {
             uchar *in = img.scanLine(j) + cinfo.output_width*3;
             QRgb *out = (QRgb*)( img.scanLine(j) );
 
-            for (uint i=cinfo.output_width; i--; ) {
-                in-=3;
+            for (uint i=cinfo.output_width; i--; ) 
+            {
+                in -= 3;
                 out[i] = qRgb(in[0], in[1], in[2]);
             }
         }
     }
+    else if ( cinfo.output_components == 4 )
+    {
+        // CMYK conversion
+        for (uint j=0; j<cinfo.output_height; j++)
+        {
+            uchar *in = img.scanLine(j) + cinfo.output_width*4;
+            QRgb *out = (QRgb*)( img.scanLine(j) );
 
+            for (uint i=cinfo.output_width; i--; )
+            {
+                in -= 4;
+                int k = in[3];
+                out[i] = qRgb(k * in[0] / 255, k * in[1] / 255, k * in[2] / 255);
+            }
+        }
+    }
+
     int newMax = QMAX(cinfo.output_width, cinfo.output_height);
     int newx = cachedSize_*cinfo.output_width / newMax;
     int newy = cachedSize_*cinfo.output_height / newMax;
@@ -553,10 +596,10 @@
 
 bool kio_digikamthumbnailProtocol::loadImlib2(QImage& image, const QString& path)
 {
-    Imlib_Image imlib2_im =
-        imlib_load_image_immediately_without_cache(QFile::encodeName(path));
+    Imlib_Image imlib2_im = imlib_load_image_immediately_without_cache(QFile::encodeName(path));
 
-    if (imlib2_im == NULL) {
+    if (imlib2_im == NULL) 
+    {
         return false;
     }