Ppm sample file

Note that a few of the test images do not contain stop signs. Running your algorithm on these images may help you identify potential false alarms e. Image set 1: Download zip archive of. Note: The above archive of ppm files is very large. Alternatively, you can download a zip archive of the images in.

Sample output for image set 1 These are sample output images generated by running a subset of image set 1 through David's TA's implementation of assignment 1. Of course, these results are just samples; your detector will undoubtedly produce different outputs due to different model parameters, etc. Image set 2: Download zip archive of. Image set 2 contains a few more difficult images to test the robustness of your model.

If it is "P3" then the image is given as ASCII text, the numerical value of each pixel ranges from 0 to the maximum value given in the header. The lines should not be longer than 70 characters. If the PPM magic identifier is "P6" then the image data is stored in byte format, one byte per colour component r,g,b.

Comments can only occur before the last field of the header and only one byte may appear after the last header field, normally a carriage return or line feed. Note that "P6" PPM files can only be used for single byte colours. This format is identical to the above except it stores greyscale information, that is, one value per pixel instead of 3 r,g,b.

The only difference in the header section is the magic identifiers which are "P2" and "P5", these correspond to the ASCII and binary form of the data respectively. Traditionally "0" refers to white while "1" refers to black. The header is identical to PPM and PGM format except there is no third header line the maximum pixel value doesn't have any meaning.

The magic identifier for PBM is "P1". The package also includes simple tools for manipu- lating portable bitmaps. The package consists of four upwardly compatible sections: pbm Supports monochrome bitmaps 1 bit per pixel. Reads either pbm or pgm formats and writes pgm format. They provide an overview of the contents of the image. For this assignment it will always be P3. Next comes the number of columns and the number of rows in the image.

The example is a 4 pixel by 4 pixel image Finally, we have the maximum color value. This defines the scale of values possible for the color intensities. This can be any value, but a common value is , meaning the red, green, and blue values for a pixel can range from a value of 0 upto The way you see the header presented is how it should be spaced out.