That’s a good start, but I want to explore this idea further. Of course one quick fix for this is to just open up the image in a raster graphics editor, save it, and then the editor will write new metadata to the image for you, thus altering its contents without altering the actual image. Since almost all of the images I used the hex editor on were PNGs, and I didn’t do anything with the JPEG beyond just changing the metadata, I will be focusing all my attention on the PNG format from now on. So I had to look for other things, partly through reverse engineering, and partly through doing some minimal research on the file formats. There was no junk data for me to trivially change. This was true of screenshots that had never been touched by an editor. I figured some arbitrary modifications to the date and time wouldn’t hurt.īut then there were images that didn’t have any metadata. In this screenshot we see metadata from both the camera that took the picture as well as GIMP as I used it to edit the image. Since metadata has no effect on the actual pixel data of the image, you can easily change it without damaging anything. I started with what I figured would be the easiest thing to find: metadata. I used the hex editor known as FlexHex to do this.įirst I opened the one JPEG that I had. That means figuring out how something is built by making small changes and seeing if you break anything. I used a method of reverse engineering that I like to call the trial-end-error method. The next step is obvious: Open the images up in a hex editor and start poking around. For now, basically all I have is the compressed version of an image, and I have to alter that somehow without corrupting it and without changing its visual appearance. I could download a steganography program to do it, but I tend to want to figure out how to do those things on my own. This of course poses an interesting question: How do you change the contents of an image without changing its visual representation on the computer screen? I could borrow methods from steganography, where you decompress an image so you can access the actual pixel values, and then change the lowest-order bits in the red, green, and blue channels of each pixel, but I don’t know enough about the image formats in question to be able to do that intelligently. One creative way I’ve thought of to get around this problem is to delete the images from my site and then upload modified versions of the images that look exactly the same visually but are not the same file. In the case of images, if I have them uploaded for a draft but I don’t post them until several days later, Google might refuse to index the images because they’re not new. One problem that I want to solve is Google’s penalizing of duplicate or old content. This research basically consists of searching for my own pages on Google to see what’s been indexed and how the pages rank. ini to use the hex editor by default: "workbench.So recently I’ve been doing some SEO research for my site. For example, this would associate all files with extensions. The hex editor can be set as the default editor for certain file types by using the workbench.editorAssociations setting. Trigger the command palette (F1) -> Reopen With -> Hex Editor. Trigger the command palette (F1) -> Open File using Hex Editor.Right click a file -> Open With -> Hex Editor.There are three ways to open a file in the hex editor: Editing with undo, redo, copy, and paste support.A data inspector for viewing the hex values as various different data types.A custom editor extension for Visual Studio Code which provides a hex editor for viewing and manipulating files in their raw hexadecimal representation.
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