image manipulation in ruby

It deals with the basics of image manipulation. It also covers few gems present in ruby for this purpose

Transcript

1. IMAGE IMAGE MANIPULATION MANIPULATION
2. INTRODUCTION • Image is a function of two real variables.The co-ordinates can be used to depict various entities for eg. the amplitude of the function can be used to depict the associated brightness. • It is a two dimensional signal ,so normal signal processing techniques can be used to process the signal
3. TYPES OF IMAGES • Vector images
4. • Raster Images
5. ADVANTAGES OF RASTER IMAGES • Easy to create • Cost effective • Pixel position can be easily calculated by cell matrix and hence can be easily manipulated DISADVANTAGES OF RASTER IMAGES • Upward scaling: blurred pictures • Higher resolution and anti alaising required
6. ADVANTAGES OF VECTOR IMAGES • Scalability : clarity is maintained even after zooming in • Size : they have a much smaller size as compared to corressponding bitmaps DISADVANTAGES OF VECTOR IMAGES • Scalability : can be scaled only upto 20% • Noise interferance : can be easily contaminated by noise (like any other analog signal)
7. DIGITIZATION OF IMAGES
8. VECTOR TO RASTER
9. RASTER TO VECTOR
10. IMAGE MANIPULATION • Image manipulation is done basically to achieve three goals – Image processing – Image analysis – Image description
11. IMAGE MANIPULATION TECHNIQUES IN RUBY • There are variety of gems available for image processing and manipulation – RMagick – Chunky_png – Phashion
12. RMAGICK • RMagick = Ruby + Image Magick • Compatible with .png as well as .jpeg files • Easy to use • Faster implimentation
13. IMPLEMENTATION Cropping an image
14. – Image1 ----- crop -----> Image2
15. • Flipping an image
16. Image1 -----flip -----> Image2
17. Watermarking
19. – Image1 --- watermarking---> Image2
20. CHUNKY_PNG • Effective for .png files only • Pure ruby based • Doesnot have any special dependencies
21. IMPLEMENTATION • Rotating image
22. • Image1 ---rotate counter_clockwise --> image2
23. • Compose
25. • Marking the difference
26. Image1 Image2
30. • Answer =>
31. • Difference mapping diff image
32. PROBLEMS?? • Can be used with PNG images only • Size compatibility • Detecting duplicate images
33. • DIFFERENCE BETWEEN COMPOSE AND WATERMARKING??
34. BLENDING!!
36. PHASHION • Detecting duplicate and nearly duplicate images
37. Image1.duplicate?(image2) => true image 1 image2
38. THANK YOU !!! THANK YOU !!!