Abstract: Systems and methods for target region evaluation and feature point evaluation are provided. The methods may include obtaining an image including a target region and extracting a plurality of feature points associated with the target region. The methods may further include, for each of the plurality of feature points, determining a sub-region including the feature point. The methods may further include performing a first grouping operation on the plurality of feature points to generate a plurality of first groups of sub-regions according to a first rule, and determining, based on the plurality of first groups of sub-regions, a confidence level associated with the target region using a plurality of trained models for processing the plurality of first groups of sub-regions, respectively. Each of the plurality of trained models may be associated with a set of model parameters. At least two sets of model parameters may be different.

Abstract: The present invention relates to a preparation method of 4-(4-amino-3-fluorophenoxy)-N-methylpyridine-2-formamide capable of enabling 4-chlorine-N-methylpyridine-2-formamide to react with 4-amino-3-fluorophenol in the presence of an inorganic base. The present invention employs the inorganic base to replace potassium t-butoxide in the prior art, thus effectively solving the problem of a potential safety hazard of the potassium t-butoxide in industrial production. In addition, after the reaction is completed, the present invention employs a crystallization method for separation to obtain a reaction product; thus compared with the methods of extraction, concentration and column isolation and purification employed in the prior art, the present invention has a simpler operation and a lower cost, results in less environment pollution and a higher yield, and is very suitable for industrial production.

Abstract: The present invention relates to a preparation method of 4-(4-amino-3-fluorophenoxy)-N-methylpyridine-2-formamide capable of enabling 4-chlorine-N-methylpyridine-2-formamide to react with 4-amino-3-fluorophenol in the presence of an inorganic base. The present invention employs the inorganic base to replace potassium t-butoxide in the prior art, thus effectively solving the problem of a potential safety hazard of the potassium t-butoxide in industrial production. In addition, after the reaction is completed, the present invention employs a crystallization method for separation to obtain a reaction product; thus compared with the methods of extraction, concentration and column isolation and purification employed in the prior art, the present invention has a simpler operation and a lower cost, results in less environment pollution and a higher yield, and is very suitable for industrial production.