US 11,756,181 B2
Method for performing image processing for determining image defect in mixed-color test image through image reading
Kanako Morimoto, Osaka (JP); Kazunori Tanaka, Osaka (JP); Koji Sato, Osaka (JP); Takuya Miyamoto, Osaka (JP); and Rui Hamabe, Osaka (JP)
Assigned to KYOCERA Document Solutions Inc., Osaka (JP)
Filed by KYOCERA Document Solutions Inc., Osaka (JP)
Filed on Dec. 21, 2021, as Appl. No. 17/558,496.
Claims priority of application No. 2020-214843 (JP), filed on Dec. 24, 2020.
Prior Publication US 2022/0207705 A1, Jun. 30, 2022
Int. Cl. G06T 7/00 (2017.01); G06K 15/02 (2006.01)
CPC G06T 7/0004 (2013.01) [G06K 15/027 (2013.01); G06T 2207/10024 (2013.01); G06T 2207/30144 (2013.01)] 6 Claims
OG exemplary drawing
 
1. An image processing method performed by a processor for determining an image defect in a test image obtained through an image reading process performed on an output sheet output by an image forming apparatus, the image processing method comprising:
deriving, by the processor, a vertical data string that is composed of data about horizontal representative values serving as representative values of a plurality of pixel values in each line in a horizontal direction in the test image;
determining, by the processor, presence or absence of at least one periodicity set in advance in the vertical data string by performing frequency analysis on the vertical data string; and
determining, by the processor, occurrence or non-occurrence and cause of periodic density unevenness serving as a type of the image defect according to a determination result on the periodicity.