Method for detecting defocused photographic image

Claim 1

A method for detecting a defocused photographic image comprising the steps of: measuring a transmittivity or a transmission density of an image recorded on a photographic film by consecutively measuring same by scanning with two photometric systems having different measuring areas; calculating measured distribution of differences between two measured values in the transmittivity or the transmission density; obtaining contrast values which have been obtained by totalling local contrasts which have been measured all over said photographic film; detecting a defocused photographic image from a determination of the relationship between said measured distribution of differences and said contrast values; wherein when the number of measurement spots used by said photometric systems is m (wherein m>2), calculating said measured distribution comprises the step of calculating either an averaged value of absolute values or an averaged value of n (wherein 1≦n<m/2) absolute values from a maximum value.

Claim 2

A method for detecting a defocused photographic image comprising the steps of: measuring a transmittivity or a transmission density of an image recorded on a photographic film by consecutively measuring same by scanning with two photometric systems having different measuring areas; calculating measured distribution of differences between two measured values in the transmittivity or the transmission density; obtaining contrast values which have been obtained by totalling local contrasts which have been measured all over said photographic film; detecting a defocused photographic image from a determination of the relationship between said measured distribution of differences and said contrast values; wherein when the number of measurement spots used by said photometric systems is m (wherein m>2), calculating said measured distribution comprises the step of calculating either an averaged value of absolute values or an averaged value of n (wherein 1≦n<m/2) absolute values from a maximum value.

Claim 3

A method for detecting a defocused photographic image comprising the steps of: measuring a transmittivity or a transmission density of an image recorded on a photographic film by consecutively measuring same by scanning with two photometric systems having different measuring areas; calculating measured distribution of differences between two measured values in the transmittivity or the transmission density; obtaining contrast values which have been obtained by totalling local contrasts which have been measured all over said photographic film; detecting a defocused photographic image from a determination of the relationship between said measured distribution of differences and said contrast values; wherein, when the number of the measurement spots used by said photometric systems is m (wherein m>2), calculating said measured distribution comprises the step of calculating an nth absolute value from a maximum value (wherein 1≦n<m/2).

Claim 4

A method for detecting a defocused photographic image comprising the steps of: measuring a transmittivity or a transmission density of an image recorded on a photographic film by consecutively measuring same by scanning with two photometric systems having different measuring areas; calculating measured distribution of differences between two measured values in the transmittivity or the transmission density; obtaining contrast values which have been obtained by totalling local contrasts which have been measured all over said photographic film; detecting a defocused photographic image from a determination of the relationship between said measured distribution of differences and said contrast values; wherein, when the number of the measurement spots used by said photometric systems is m (wherein m>2), calculating said measured distribution comprises the step of calculating an nth absolute value from a maximum value (wherein 1≦n<m/2).

Claim 5

A method for detecting defocused photographic image which comprises the steps of: optically scanning a photographic film, said film being scanned optically in two concentric picture elements consisting of a larger picture element and a smaller picture element, with different measuring areas; and, when a transmittivity or a transmission density at column i and row j of said larger picture element is DL ij while a transmittivity or a transmission density at column i and row j of said smaller picture element is DS ij , a difference between them D ij is calculated by the following equation: ΔD.sub.ij =|DL.sub.ij -DS.sub.ij |; and then a value D max ·n at an nth (1-m/2) from a maximum of the difference ΔD ij corresponding to all picture elements m is plotted on a first axis while an absolute value DB of a density difference between respective adjacent sampling points either in said larger picture element or in said smaller picture element, ##EQU3## is plotted on a second axis; and defocused images on said photographic film are detected from a determination of the distribution of said D max ·n and DB.

Claim 6

A method for detecting defocused photographic image which comprises the steps of: optically scanning a photographic film, said film being scanned optically in two concentric picture elements consisting of a larger picture element and a smaller picture element, with different measuring areas; and, when a transmittivity or a transmission density at column i and row j of said larger picture element is DL ij while a transmittivity or a transmission density at column i and row j of said smaller picture element is DS ij , a difference between them D ij is calculated by the following equation: ΔD.sub.ij =|DL.sub.ij -DS.sub.ij |; and then a value D max ·n at an nth (1-m/2) from a maximum of the difference ΔD ij corresponding to all picture elements m is plotted on a first axis while an absolute value DB of a density difference between respective adjacent sampling points either in said larger picture element or in said smaller picture element, ##EQU3## is plotted on a second axis; and defocused images on said photographic film are detected from a determination of the distribution of said D max ·n and DB.