Fix PNG resolution metadata.

mdboom · mdboom · commit 97e6b34f6e8a · 2010-05-06T18:40:31.000Z
svn path=/trunk/matplotlib/; revision=8298
diff --git a/src/_png.cpp b/src/_png.cpp
@@ -140,7 +140,7 @@ Py::Object _png_module::write_png(const Py::Tuple& args)
     // Save the dpi of the image in the file
     if (args.size() == 5) {
       double dpi = Py::Float(args[4]);
-      size_t dots_per_meter = (size_t)(dpi / (2.54 / 100.0));
+      size_t dots_per_meter = (size_t)(dpi * 2.54 * 100.0);
       png_set_pHYs(png_ptr, info_ptr, dots_per_meter, dots_per_meter, PNG_RESOLUTION_METER);
     }
 

Original file line number	Diff line number	Diff line change
`@@ -140,7 +140,7 @@ Py::Object _png_module::write_png(const Py::Tuple& args)`
`140`	`140`	`// Save the dpi of the image in the file`
`141`	`141`	`if (args.size() == 5) {`
`142`	`142`	`double dpi = Py::Float(args[4]);`
`143`		`- size_t dots_per_meter = (size_t)(dpi / (2.54 / 100.0));`
	`143`	`+ size_t dots_per_meter = (size_t)(dpi * 2.54 * 100.0);`
`144`	`144`	`png_set_pHYs(png_ptr, info_ptr, dots_per_meter, dots_per_meter, PNG_RESOLUTION_METER);`
`145`	`145`	`}`
`146`	`146`