Vision API pixelFractions don't add up #2383
Description
I am evaluating Vision API for color detection and ran into this issue:
I've uploaded an image of a rainbow to https://cloud.google.com/vision/docs/drag-and-drop
and got the following for image properties:
"imagePropertiesAnnotation": {
"dominantColors": {
"colors": [
{
"color": {
"red": 3,
"green": 2,
"blue": 253
},
"score": 0.23274913,
"pixelFraction": 0.08280405
},
{
"color": {
"red": 6,
"green": 129,
"blue": 6
},
"score": 0.22612064,
"pixelFraction": 0.10820983
},
{
"color": {
"red": 249,
"green": 249,
"blue": 10
},
"score": 0.12150193,
"pixelFraction": 0.06665099
},
{
"color": {
"red": 74,
"green": 3,
"blue": 128
},
"score": 0.057100553,
"pixelFraction": 0.10577903
},
{
"color": {
"red": 253,
"green": 168,
"blue": 3
},
"score": 0.044047087,
"pixelFraction": 0.07417862
},
{
"color": {
"red": 41,
"blue": 200
},
"score": 0.015849508,
"pixelFraction": 0.009252725
},
{
"color": {
"red": 81,
"green": 85,
"blue": 253
},
"score": 0.008871765,
"pixelFraction": 0.0034501685
},
{
"color": {
"red": 253,
"green": 2,
"blue": 3
},
"score": 0.006723068,
"pixelFraction": 0.096996784
},
{
"color": {
"red": 165,
"green": 159,
"blue": 7
},
"score": 0.0064168423,
"pixelFraction": 0.0047047753
},
{
"color": {
"red": 154,
"green": 78,
"blue": 189
},
"score": 0.0041353106,
"pixelFraction": 0.011761938
}
]
}
}things I've noticed:
pixelFractions add up to 1.0, but rather to 0.5637 and scores to ~0.7235...
Why is that, where does the rest of the pixels go?
I also uploaded the following image:
(single color red block)
and that gives expected 1 and 1 for pixelFraction and score
Sincerely,
Alexander