fcalvo Posted January 25, 2005 Share Posted January 25, 2005 Just download this image and modify brightness to at around -80 and contrast upto around +80. It is very well done. Link to comment Share on other sites More sharing options...
frank_dzambic Posted January 25, 2005 Share Posted January 25, 2005 Wow, that is so cool. How do they do that???? Link to comment Share on other sites More sharing options...
paulglenn Posted January 25, 2005 Share Posted January 25, 2005 Apparently, with underwear that is several sizes too small. Link to comment Share on other sites More sharing options...
emre Posted January 25, 2005 Share Posted January 25, 2005 The first operation eliminates unwanted information from the shadows, the second operation eliminates unwanted information from the highlights. What you are left with is this image. Basically what you do is to superimpose two images, then find a series of operations that eliminates the unwanted one. Link to comment Share on other sites More sharing options...
fcalvo Posted January 25, 2005 Author Share Posted January 25, 2005 You are right Emre, and they must be doing this by interpolating the pixels of both images. If you zoom in at pixel level you'll see that it seems to be 1 pixel of 1 image and the next from the other image. Or something like that... I wonder if there are any PS plugin to do this. Link to comment Share on other sites More sharing options...
dave_kendall Posted January 25, 2005 Share Posted January 25, 2005 I gave it a try. Here's how I did it. 1. Create a checker pattern. File>new> 2x2 pixels. Make the top left and bottom right black. then click edit>define pattern. 2. Now Take image A (photo of my wife) convert it to b&w, drop the contrast and bump the brightness (this you'll have to experiment with). 3. Take image B (coloseum) and put it in a layer under image A. 4. Create a mask on image A, choose fill tool, choose pattern and then select the pattern you created in the first step. fill your checkered patern on the mask. now you have two interlaced images! you'll probably have to do some fine tuning at this point. Oh yeah and you may have switch between indexed color, and rgb a couple times. it's not perfect, but it gives you the idea. here's my go at it: Link to comment Share on other sites More sharing options...
grant_. Posted January 26, 2005 Share Posted January 26, 2005 my brightness doesnt go to -80, it goes to 0....wtf Link to comment Share on other sites More sharing options...
emre Posted January 26, 2005 Share Posted January 26, 2005 That can't be right; zero means no change: http://computer-darkroom.com/tutorials/tutorial_3_1.htm Link to comment Share on other sites More sharing options...
fcalvo Posted January 26, 2005 Author Share Posted January 26, 2005 Brilliant Dave! I'll give it a try. Link to comment Share on other sites More sharing options...
sprouty Posted January 26, 2005 Share Posted January 26, 2005 I'm with Grant, my monitor only goes from 0 - 100? Link to comment Share on other sites More sharing options...
dave_kendall Posted January 26, 2005 Share Posted January 26, 2005 you don't do the changes on your monitor. you have to save this image, and then open it in photoshop. Image>Adjustments>Brightness/Contrast... Link to comment Share on other sites More sharing options...
frank_dzambic Posted January 26, 2005 Share Posted January 26, 2005 Wow, nice piece of reverse engineering Dave. I just noticed as well, when I go to File--Open and only single click on either your image, or the one above, it comes up in a definite checkerboard pattern in the little preview window. Link to comment Share on other sites More sharing options...
emre Posted January 26, 2005 Share Posted January 26, 2005 We are talking about the Brightess/Contrast tool in Photoshop, not the monitor's settings! Link to comment Share on other sites More sharing options...
sprouty Posted January 26, 2005 Share Posted January 26, 2005 Thanks Emre, now I see the 1/2-neked wimin. Link to comment Share on other sites More sharing options...
kyle baker Posted January 26, 2005 Share Posted January 26, 2005 you can also see the images if you are using a laptop and you tilt the display way back. Guess this would work on an LCD monitor too. not sure about a crt tho. Link to comment Share on other sites More sharing options...
john_baker8 Posted January 26, 2005 Share Posted January 26, 2005 I do not know about your monitors, but these pictures are reaking havok on my LCD display. The scan lines on the pictures are just flittering all over the place. Very strange. Link to comment Share on other sites More sharing options...
stefanovandelli Posted January 27, 2005 Share Posted January 27, 2005 No need to download the image. Just press CTRL+A while looking at this forum thread. Link to comment Share on other sites More sharing options...
malcolmdwyer Posted January 27, 2005 Share Posted January 27, 2005 <p>So why is there such a huge difference between LCD and CRT here? I was intially looking at this with CRT and I couldn't even detect the checkerboard at all without zooming in. On the LCD it is completely obvious.</p> <p>Is it just my CRT? I'm comparing a 21" CRT at 1600x1200 to a 15" laptop LCD at 1024x768. Is the CRT really losing that much of the high frequency information that it gets completely smoothed out? It is being driven through a KVM switch, so I'm probably losing some detail there.</p> <p>Anyway... For those who are still wondering what's going on here... The two images reside in different parts of the histogram, with the main image dominting the middle and low values, and the hidden image in the brightest values. The entire range of brightness in the hidden image is also compressed into only the few highest values. By bringing the brightness way down, you push the main image into black, and bring the hidden image down into the middle range (but it's still just a few values around middle gray). Then you crank up the contrast and that expands the values in the middle of the histogram out to the full range from black to white.</p> Malcolm Link to comment Share on other sites More sharing options...
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