Stephen J. Guy

Many Digital Cameras include timestamp directly on image Metadata in binary image deprecates need for visible timestamp Experienced Photoshop users can fix images Bad for novices No batch processing

Time stamp on a picture? Is there a way to remove a time stamp from a picture already taken? Some online (free) program? I took a picture that is basically ruined due to where the time stamp is at. :( I just want to know if there's a way of removing it (if you have the program to do so, help!) 3 months ago Additional Details 3 months ago This is the picture /P /P... 3 months ago Ok, photo-shop people. 10 points goes to whoever removes that time stamp successfully! I do not have Photoshop. :( Image referenced with timestamp

No Paper on how to do it (Not been done before?) No easy database of timestamped images Timestamps differ in: Color – (Red, Orange, Yellow, Blue, & White) Length – (From “ ” to “2004/01/01 00:14:10”) Num of Lines – Both 1 and 2 line timestamps Position & Orientation JPEG Compression!! Timestamp is different color from “original” Timestamp color depends on picture content Timestamp color varies throughout picture Blur Edges

Common Timestamp Features Position: Near corners Color Value: Timestamps are bright unnatural colors  High Value Color Saturation: Timestamp are not greyish (dull)  Med-High saturation* Gradient Magnitude: Text is high frequency  strong edges Position Saturation & ValueGradient Magnitude

1) Find all pixels that meet all features 2) Median Filter 3) Create color model from pixels in corner 4) Choose corners with timestamp (most pixels) 5) Select all pixels which meet color model 6) Dilate selection for a safety buffer

Decimate the timestamp Thresholding is to simple a selection criteria Select the wrong corner Most timestamp pixels is to simple a model Creating the wrong color model Assuming only 1 color will pass the thresholds is naïve Dilation may be overly aggressive Simply dilating n-pixels is too simple Dilatation may be underly aggressive Simply dilating n-pixels is too simple

The Clown’s hair meets all my criteria – It’s oddly colored, vibrant, has large gradients, and near a corner

A more serious failure: Grass is highly textured, saturated, and bright

JPEG Compression causes problems

Fill in timestamp with Efros &Leung style texture synthesis Fill order: Pixels with the most non-timestamp neighbors are filled 1 st Only patches form the corner are used as a source for synthesis Fill order: Black to Red

Slow Only Take samples from timestamp corner Patch Size can be difficult to choose Fails with structured textures

Better Texture Synthesis Gradient oriented hole filling (Criminisi et. al) Faster Texture Synthesis More robust timestamp detection Currently ignore gradient magnitude when finalizing timestamp