steganography

问题 How can I add text to a pdf document, which is not visible? The document manipulation should be done in java. The usecase is to add further metadata to a document (in a proprietary format, about 40kb), before the document is signed and archived. I tried: annotation field with size 0,0 .txt file attachment but, this annoys readers of the PDF, because they see a difference (comment / attachment bar). Is there a comment object or a syntax to comment out lines in a PDF document? EDIT: I've tried

问题 I am extracting frames from video with the help of VideoCapture. Extracted the first frame converted the frame into an image with the help of PIL. Printed the previous pixel value at position (1,1) Printed the pixel value at position(1,1) of the newly created image Can anyone explain why? Function to extract frames import cv2 from PIL import Image def FrameCapture(path): # Path to video file vidObj = cv2.VideoCapture(path) fourcc = cv2.VideoWriter_fourcc(*'mp4v') width = cv2.CAP_PROP_FRAME

问题 I am extracting frames from video with the help of VideoCapture. Extracted the first frame converted the frame into an image with the help of PIL. Printed the previous pixel value at position (1,1) Printed the pixel value at position(1,1) of the newly created image Can anyone explain why? Function to extract frames import cv2 from PIL import Image def FrameCapture(path): # Path to video file vidObj = cv2.VideoCapture(path) fourcc = cv2.VideoWriter_fourcc(*'mp4v') width = cv2.CAP_PROP_FRAME

问题 I am implementing a video steganography for my project. I came across the algorithm from here . i have tried and tested the code and the embedding part is working fine. But i encountered a problem with the readByte which is the last method in the VideoSteganography class. The method Gives ArrayIndexOutOfBoundsException . Below is the method. I pass the parameters as String fname = jTextField3.getText(); File fil = new File(fname); String password = "123456"; SteganoInformation cls = new

问题 I am using a startech capture card for capturing video from the source machine..I have encoded that video using matlab so every frame of that video will contain that marker...I run that video on the source computer(HDMI out) connected via HDMI to my computer(HDMI IN) once i capture the frame as bitmap(1920*1080) i re-size it to 1280*720 i send it for processing , the processing code checks every pixel for that marker. The issue is my capture card is able to capture only at 1920*1080 where as

问题 I am using a startech capture card for capturing video from the source machine..I have encoded that video using matlab so every frame of that video will contain that marker...I run that video on the source computer(HDMI out) connected via HDMI to my computer(HDMI IN) once i capture the frame as bitmap(1920*1080) i re-size it to 1280*720 i send it for processing , the processing code checks every pixel for that marker. The issue is my capture card is able to capture only at 1920*1080 where as

问题 I'm working on a project where I edit the pixels of a jpg in PHP using the GD library. Its very crucial and key to my project that the output from PHP retains the pixel values I set (cough-steganography-cough). This is the first time I've attempted image manipulation in PHP. I've had no problems before in my Java implementations, so I was foolish not to investigate GD's jpeg compression quality before pursuing further. It turns out that after all my effort, my code does not function the way

问题 Closed . This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be answered with facts and citations by editing this post. Closed 5 years ago . I'm really curious about that because nowadays every channel could modify or compress images some way which could be considered as a attack on steganography. We can divide steganography to two basic types, first operates on spatial domain of image and second operates on some

问题 So here is what I was trying to do. I'm absolutely new to matlab. It has only been a day or so that I've used it and here is a little something that my teacher had asked me to do. Embed statements or group of strings within an image using the LSB Algorithm. The string is to be read from a file. As of now, I've not used any file operations. I'm trying this using one character and I don't know whats wrong. The algo seems simple but my output i.e, both the cover and the steg pixels show the same

问题 So here is what I was trying to do. I'm absolutely new to matlab. It has only been a day or so that I've used it and here is a little something that my teacher had asked me to do. Embed statements or group of strings within an image using the LSB Algorithm. The string is to be read from a file. As of now, I've not used any file operations. I'm trying this using one character and I don't know whats wrong. The algo seems simple but my output i.e, both the cover and the steg pixels show the same