Hiding secret data in digital images is one of the major researchfields in information security.Recently,reversible data hiding in encrypted images has attracted extensive attention due to the emergence of cloud servi...Hiding secret data in digital images is one of the major researchfields in information security.Recently,reversible data hiding in encrypted images has attracted extensive attention due to the emergence of cloud services.This paper proposes a novel reversible data hiding method in encrypted images based on an optimal multi-threshold block labeling technique(OMTBL-RDHEI).In our scheme,the content owner encrypts the cover image with block permutation,pixel permutation,and stream cipher,which preserve the in-block correlation of pixel values.After uploading to the cloud service,the data hider applies the prediction error rearrangement(PER),the optimal threshold selection(OTS),and the multi-threshold labeling(MTL)methods to obtain a compressed version of the encrypted image and embed secret data into the vacated room.The receiver can extract the secret,restore the cover image,or do both according to his/her granted authority.The proposed MTL labels blocks of the encrypted image with a list of threshold values which is optimized with OTS based on the features of the current image.Experimental results show that labeling image blocks with the optimized threshold list can efficiently enlarge the amount of vacated room and thus improve the embedding capacity of an encrypted cover image.Security level of the proposed scheme is analyzed and the embedding capacity is compared with state-of-the-art schemes.Both are concluded with satisfactory performance.展开更多
Aim To separate texts from graphics on mechanical engineering drawings. Methods By improved labeling run, the size of circumscribed rectangle and pixel density about the connected graphs on a drawing were gained,...Aim To separate texts from graphics on mechanical engineering drawings. Methods By improved labeling run, the size of circumscribed rectangle and pixel density about the connected graphs on a drawing were gained, according to these value, texts not sticking to graphics could be separated from a drawing. The concept of appendant block was introduced, using the appendant block, texts sticking to graphics could be determined and cut. Results Texts and symbols on mechanical engineering drawings can be separated well. Conclusion This method is simple and fast, it does not destroy the shape of texts and symbols, it can be used for separating texts and symbols from all linear graphics.展开更多
基金the Ministry of Science and Technology of Taiwan,Grant Number MOST 110-2221-E-507-003.
文摘Hiding secret data in digital images is one of the major researchfields in information security.Recently,reversible data hiding in encrypted images has attracted extensive attention due to the emergence of cloud services.This paper proposes a novel reversible data hiding method in encrypted images based on an optimal multi-threshold block labeling technique(OMTBL-RDHEI).In our scheme,the content owner encrypts the cover image with block permutation,pixel permutation,and stream cipher,which preserve the in-block correlation of pixel values.After uploading to the cloud service,the data hider applies the prediction error rearrangement(PER),the optimal threshold selection(OTS),and the multi-threshold labeling(MTL)methods to obtain a compressed version of the encrypted image and embed secret data into the vacated room.The receiver can extract the secret,restore the cover image,or do both according to his/her granted authority.The proposed MTL labels blocks of the encrypted image with a list of threshold values which is optimized with OTS based on the features of the current image.Experimental results show that labeling image blocks with the optimized threshold list can efficiently enlarge the amount of vacated room and thus improve the embedding capacity of an encrypted cover image.Security level of the proposed scheme is analyzed and the embedding capacity is compared with state-of-the-art schemes.Both are concluded with satisfactory performance.
文摘Aim To separate texts from graphics on mechanical engineering drawings. Methods By improved labeling run, the size of circumscribed rectangle and pixel density about the connected graphs on a drawing were gained, according to these value, texts not sticking to graphics could be separated from a drawing. The concept of appendant block was introduced, using the appendant block, texts sticking to graphics could be determined and cut. Results Texts and symbols on mechanical engineering drawings can be separated well. Conclusion This method is simple and fast, it does not destroy the shape of texts and symbols, it can be used for separating texts and symbols from all linear graphics.
