2.1.97 [HTML5:2014] Section 18.104.22.168 Serializing bitmaps to a file
V0220: Setting the JPEG quality to an invalid value does not cause the default value to be used
The specification states:
... Serializing bitmaps to a file ... Arguments for serialization methods [table] Other arguments [column] The second argument, if it is a number in the range 0.0 to 1.0 inclusive, must be treated as the desired quality level. If it is not a number or is outside that range, the user agent must use its default value, as if the argument had been omitted.
All document modes (All versions)
Setting the JPEG quality to an invalid value does not cause the default value to be used.