updated logic according to Larry's feedback

Signed-off-by: Lydia Zheng <[email protected]>

Author: lydia-zheng

src/oiiotool/expressions.cpp

@@ -320,29 +320,26 @@ Oiiotool::express_parse_atom(const string_view expr, string_view& s,
 
             } else if (metadata == "IS_CONSTANT") {
                 std::vector<float> color((*img)(0, 0).nchannels());
-                if (ImageBufAlgo::isConstantColor((*img)(0, 0), color)) {
+                if (ImageBufAlgo::isConstantColor((*img)(0, 0), 0.0f, color)) {
                     result = "1";
                 } else {
                     result = "0";
                 }
 
 
             } else if (metadata == "IS_BLACK") {
-                auto pixstat = ImageBufAlgo::computePixelStats((*img)(0, 0));
                 std::vector<float> color((*img)(0, 0).nchannels());
                 // Check constant first to guard against false positive average of 0 with negative values i.e. -2, 1, 1
-                if (ImageBufAlgo::isConstantColor((*img)(0, 0), color)) {
-                    // Do we need this loop if we know that all channels should be the same value in constant frame?
-                    for (size_t i = 0; i < pixstat.avg.size(); ++i) {
-                        // If any of the pixel doesn't have an average of (0,0,0), then we don't have a black frame
-                        // Is this the best way to check? Feels fishy to have the specified number...should we look at 0.0f or other formats?
-                        if (pixstat.avg[i] == 0.000000) {
-                            result = "1";
-                        } else {
-                            result = "0";
-                        }
+                if (ImageBufAlgo::isConstantColor((*img)(0, 0), 0.0f, color)) {
+                    // trusting that the constantcolor check means all channels have the same value, so we only check the first channel
+                    if (color[0] == 0.0f) {
+                        result = "1";
+                    }
+                    else {
+                        result = "0";
                     }
                 } else {
+                    // Not even constant color case -> We don't want those to count as black frames.
                     result = "0";
                 }