增加调节对比度功能 很多图片形式pdf扫描文件颜色比较浅,希望能调节对比度 3 votes Vote Vote Vote We're glad you're herePlease sign in to leave feedback Signed in as (Sign out) Close Close Vote We’ll send you updates on this idea Anonymous shared this idea · Sep 23, 2017 · Report…Report… · Delete… · Admin → How important is this to you? Not at all You must login first! Important You must login first! Critical You must login first! We're glad you're herePlease sign in to leave feedback Signed in as (Sign out) Close Close Tweet Add a comment… Remove Attachment Attach a File We're glad you're herePlease sign in to leave feedback Signed in as (Sign out) Close Close Post comment Submitting... An error occurred while saving the comment