Fix an off-by-one error in function exportImageAlpha.

ukoethe · Oct 13, 2014 · c3fb6c9 · c3fb6c9
1 parent cf86978
commit c3fb6c9
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/include/vigra/impexalpha.hxx b/include/vigra/impexalpha.hxx
@@ -789,7 +789,7 @@ namespace vigra
 
             encoder->setPixelType(pixel_type);
 
-            vigra_precondition(isBandNumberSupported(encoder->getFileType(), image_accessor.size(image_upper_left)),
+            vigra_precondition(isBandNumberSupported(encoder->getFileType(), image_accessor.size(image_upper_left) + 1U),
                                "exportImageAlpha(): file format does not support requested number of bands (color channels)");
 
             const range_t image_source_range(find_source_value_range(export_info,