Add std/png/README.md
// See the License for the specific language governing permissions and
// limitations under the License.
+// --------
+
+// Filter 1: Sub.
+
pri func decoder.filter_1!(curr: slice base.u8),
choosy,
{
@@ -72,6 +76,8 @@ pri func decoder.filter_1_distance_4_fallback!(curr: slice base.u8) {
}
}
+// Filter 2: Up.
+
pri func decoder.filter_2!(curr: slice base.u8, prev: slice base.u8),
choosy,
{
@@ -92,6 +98,8 @@ pri func decoder.filter_2!(curr: slice base.u8, prev: slice base.u8),
} endwhile
}
+// Filter 3: Average.
+
pri func decoder.filter_3!(curr: slice base.u8, prev: slice base.u8),
choosy,
{
@@ -210,6 +218,8 @@ pri func decoder.filter_3_distance_4_fallback!(curr: slice base.u8, prev: slice
}
}
+// Filter 4: Paeth.
+
pri func decoder.filter_4!(curr: slice base.u8, prev: slice base.u8),
choosy,
{
