https://github.com/ImageMagick/ImageMagick/issues/8375

Cristy · Cristy · commit dc360ceee13e · 2025-10-05T12:23:17.000-04:00
diff --git a/coders/jpeg.c b/coders/jpeg.c
@@ -1251,8 +1251,6 @@ static Image *ReadJPEGImage_(const ImageInfo *image_info,
   /*
     Set image resolution.
   */
-  image->x_resolution=DefaultResolution;
-  image->y_resolution=DefaultResolution;
   units=0;
   if (jpeg_info->saw_JFIF_marker != 0)
     {
@@ -1272,11 +1270,10 @@ static Image *ReadJPEGImage_(const ImageInfo *image_info,
           */
           if ((jpeg_info->X_density != 0) && (jpeg_info->Y_density != 0))
             {
-              double aspect_ratio = (double) jpeg_info->Y_density/
-                (double) jpeg_info->X_density;
+              double aspect_ratio = (double) jpeg_info->Y_density*
+                MagickSafeReciprocal((double) jpeg_info->X_density);
               image->y_resolution=image->x_resolution*aspect_ratio;
             }
-          units=1;
         }
     }
   if (units == 1)

Original file line number	Diff line number	Diff line change
`@@ -1251,8 +1251,6 @@ static Image ReadJPEGImage_(const ImageInfo image_info,`
`1251`	`1251`	`/*`
`1252`	`1252`	`Set image resolution.`
`1253`	`1253`	`*/`
`1254`		`- image->x_resolution=DefaultResolution;`
`1255`		`- image->y_resolution=DefaultResolution;`
`1256`	`1254`	`units=0;`
`1257`	`1255`	`if (jpeg_info->saw_JFIF_marker != 0)`
`1258`	`1256`	`{`
`@@ -1272,11 +1270,10 @@ static Image ReadJPEGImage_(const ImageInfo image_info,`
`1272`	`1270`	`*/`
`1273`	`1271`	`if ((jpeg_info->X_density != 0) && (jpeg_info->Y_density != 0))`
`1274`	`1272`	`{`
`1275`		`- double aspect_ratio = (double) jpeg_info->Y_density/`
`1276`		`- (double) jpeg_info->X_density;`
	`1273`	`+ double aspect_ratio = (double) jpeg_info->Y_density*`
	`1274`	`+ MagickSafeReciprocal((double) jpeg_info->X_density);`
`1277`	`1275`	`image->y_resolution=image->x_resolution*aspect_ratio;`
`1278`	`1276`	`}`
`1279`		`- units=1;`
`1280`	`1277`	`}`
`1281`	`1278`	`}`
`1282`	`1279`	`if (units == 1)`