AnyImageImporter: recognize TIFF files by magic.

doc/changelog.dox

@@ -44,6 +44,12 @@ See also:
 
 -   Added @ref Math::fmod() (see [mosra/magnum#454](https://github.com/mosra/magnum/pull/454))
 
+@subsection changelog-latest-changes Changes and improvements
+
+@subsubsection changelog-latest-changes-trade Trade library
+
+-   Recognizing TIFF file header magic in @ref Trade::AnyImageImporter "AnyImageImporter"
+
 @subsection changelog-latest-buildsystem Build system
 
 -   Fixed compilation of the @ref GL library on macOS with ANGLE --- new code

src/MagnumPlugins/AnyImageImporter/AnyImageImporter.cpp

@@ -165,6 +165,11 @@ void AnyImageImporter::doOpenData(Containers::ArrayView<const char> data) {
     /* https://en.wikipedia.org/wiki/Portable_Network_Graphics#File_header */
     else if(Utility::String::viewBeginsWith(data, "\x89PNG\x0d\x0a\x1a\x0a"))
         plugin = "PngImporter";
+    /* http://paulbourke.net/dataformats/tiff/,
+       http://paulbourke.net/dataformats/tiff/tiff_summary.pdf */
+    else if(Utility::String::viewBeginsWith(data, "II\x2a\x00") ||
+            Utility::String::viewBeginsWith(data, "MM\x00\x2a"))
+        plugin = "TiffImporter";
     /* https://github.com/file/file/blob/d04de269e0b06ccd0a7d1bf4974fed1d75be7d9e/magic/Magdir/images#L18-L22
        TGAs are a complete guesswork, so try after everything else fails. */
     else if([data]() {

src/MagnumPlugins/AnyImageImporter/AnyImageImporter.h

@@ -88,8 +88,8 @@ tries to open the file with it. Supported formats:
 -   Adobe Photoshop (`*.psd`), loaded with any plugin that provides `PsdImporter`
 -   Silicon Graphics (`*.sgi`, `*.bw`, `*.rgb`, `*.rgba`), loaded with any
     plugin that provides `SgiImporter`
--   Tagged Image File Format (`*.tif`, `*.tiff`), loaded with any plugin that
-    provides `TiffImporter`
+-   Tagged Image File Format (`*.tif`, `*.tiff` or data with corresponding
+    signature), loaded with any plugin that provides `TiffImporter`
 -   Truevision TGA (`*.tga`, `*.vda`, `*.icb`, `*.vst` or data with
     corresponding signature), loaded with @ref TgaImporter or any other plugin
     that provides it

src/MagnumPlugins/AnyImageImporter/Test/AnyImageImporterTest.cpp

@@ -92,6 +92,7 @@ constexpr struct {
     {"GIF", "image.gif", nullptr, "GifImporter"},
     {"PSD", "image.psd", nullptr, "PsdImporter"},
     {"TIFF", "image.tiff", nullptr, "TiffImporter"},
+    {"TIFF data", "image.tiff", fileCallback, "TiffImporter"},
     {"Basis", "rgb.basis", nullptr, "BasisImporter"}
     /* Not testing everything, just the most important ones */
 };

src/MagnumPlugins/AnyImageImporter/Test/CMakeLists.txt

@@ -53,6 +53,7 @@ corrade_add_test(AnyImageImporterTest AnyImageImporterTest.cpp
     FILES
         gray.jpg
         image.exr
+        image.tiff
         pngs.ico
         rgb.basis
         rgb.hdr