1. Slide title In CAPITALS 50 pt Slide subtitle 32 pt iPACKMAN – High-Quality, Low Complexity Texture Compression for Mobile Phones Jacob Strom Ericsson Tomas Akenine-Moller Lund University

2. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Outline  Motivation  Design Goals  Basic Idea  PACKMAN – the old version  Differential Coding  Compression  Results

3. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Why 3D Graphics… on a Mobile Phone?  Man-Machine Interfaces  Screen Savers  Games  Maps, Messaging, Browsing and more…

4. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Why is 3D Graphics Hard on a Mobile Phone? Limited resources:  Small amount of memory  Little memory bandwidth  Little chip area for special purpose  Powered by batteries

5. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Texture Compression Helps  Small amount of memory –More texture data can fit in the limited amount of memory  Little memory bandwidth –More texturing possible for same amount of bandwidth  Little chip area for special purpose –A texture cache using compressed data can be made smaller  Powered by batteries –Reduced bandwidth means lower energy consumption  from PACKMAN to iPACKMAN: complexity

6. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Previous Work SchemeComplexityQuality CCC [Campbell et al. ’86]Low – but uses indirect addressing Medium/Low

7. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Previous Work SchemeComplexityQuality CCC [Campbell et al. ’86]Low – but uses indirect addressing Medium/Low S3TC/DXTC [Iourcha et al. ‘99]Medium/High – performs multiplication with 1/3 and 2/3 High

8. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Previous Work SchemeComplexityQuality CCC [Campbell et al. ’86]Low – but uses indirect addressing Medium/Low S3TC/DXTC [Iourcha et al. ‘99]Medium/High – performs multiplication with 1/3 and 2/3 High PVR-TC [Fenney ’03]Medium/High – bilinear upscaling High

9. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Previous Work SchemeComplexityQuality CCC [Campbell et al. ’86]Low – but uses indirect addressing Medium/Low S3TC/DXTC [Iourcha et al. ‘99]Medium/High – performs multiplication with 1/3 and 2/3 High PVR-TC [Fenney ’03]Medium/High – bilinear upscaling High ???LowHigh

10. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Design Goals  Low Decompression Complexity –8 parallel units needed for one trilinear operation per clock –mobile devices have very little surface area to spare  High Image Quality –Should be on par with, or better than, industry standard DXTC at the same bit rate  Should be “system friendly” –You want to be able to store compressed data in the cache, and that means that the decompression needs to be simple and fast. –No indirect data such as a color palette that increases latency –No data from adjacent blocks should be needed –For systems without a texture cache, a block size of 32 bits would be preferable, matching the size of the bus.

11. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Basic Idea PACKMAN  The Human Visual System is more sensitive to luminance than to chrominance  In video and still image coding, chrominance information is most often subsampled in the x- and y- direction (MPEG, JPEG, H263, H264 etc). Loosely speaking, chrominance is defined per 2x2 block.  PACKMAN has basically only one color per 2x4 block. The rest is luminance information  Code each 2x4 block using 32 bits

12. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Basic Idea PACKMAN  Use only 12 bits to specify a “base color” for a 2x4 block 12-bit “base color”

13. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Basic Idea PACKMAN  Use only 12 bits to specify a “base color” for a 2x4 block  Modify the luminance for each pixel in the block + per-pixel luminance 12-bit “base color”

14. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Basic Idea PACKMAN  Use only 12 bits to specify a “base color” for a 2x4 block  Modify the luminance for each pixel in the block += per-pixel luminance resulting image 12-bit “base color”

15. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Luminance modification  Only one value per pixel needed to specify luminance

16. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Luminance modification  Only one value per pixel needed to specify luminance R = 17 G = 34 B = 204 Base Color

17. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Luminance modification  Only one value per pixel needed to specify luminance R = 17 G = 34 B = 204 Base Color +110 Add same value

18. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Luminance modification  Only one value per pixel needed to specify luminance R = 17 G = 34 B = 204 Base Color +110 Add same value = 127 = 144 = 255 (after clamping) Resulting Color

19. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt How to Specify Luminance  Two bits per pixel are used to specify the luminance. Modifier is one out of four values.  Problem: Small values [-8, -2, 2, 8]

20. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt How to Specify Luminance  Two bits per pixel are used to specify the luminance. Modifier is one out of four values.  Problem: Small values [-8, -2, 2, 8] –smooth transitions OK

21. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt How to Specify Luminance  Two bits per pixel are used to specify the luminance. Modifier is one out of four values.  Problem: Small values [-8, -2, 2, 8] –smooth transitions OK –sharp edges bad

22. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt How to Specify Luminance  Two bits per pixel are used to specify the luminance. Modifier is one out of four values.  Problem: Small values [-8, -2, 2, 8] –smooth transitions OK –sharp edges bad  Big values [-255, -127, 127, 255] –sharp edges OK

23. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt How to Specify Luminance  Two bits per pixel are used to specify the luminance. Modifier is one out of four values.  Problem: Small values [-8, -2, 2, 8] –smooth transitions OK –sharp edges bad  Big values [-255, -127, 127, 255] –sharp edges OK –smooth transitions bad

24. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt How to Specify Luminance  Two bits per pixel are used to specify the luminance. Modifier is one out of four values.  Problem: Small values [-8, -2, 2, 8] –smooth transitions OK –sharp edges bad  Big values [-255, -127, 127, 255] –sharp edges OK –smooth transitions bad  Solution: Codebook of tables, one/block.

25. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Modifier Codebook  We created the codebook from random numbers by minimizing the error for a set of images. ??

26. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Modifier Codebook  We created the codebook from random numbers by minimizing the error for a set of images. -8-228 -12-4412 -16-4416 -24-8824 -31-6631 -34-121234 -47-191947 -50-8850 -62-121262 -68-242468 -80-282880 -94-383894 -100-1616100 -127-4242127 -160-5656160 -254-8484254

27. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Modifier Codebook  We created the codebook from random numbers by minimizing the error for a set of images. –Simulated Annealing –Modified version of LBG-algorithm  Symmetry was enforced to reduce on-chip memory -8-228 -12-4412 -16-4416 -24-8824 -31-6631 -34-121234 -47-191947 -50-8850 -62-121262 -68-242468 -80-282880 -94-383894 -100-1616100 -127-4242127 -160-5656160 -254-8484254

28. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Modifier Codebook  We created the codebook from random numbers by minimizing the error for a set of images. –Simulated Annealing –Modified version of LBG-algorithm  Symmetry was enforced to reduce on-chip memory -8-228 -12-4412 -16-4416 -24-8824 -31-6631 -34-121234 -47-191947 -50-8850 -62-121262 -68-242468 -80-282880 -94-383894 -100-1616100 -127-4242127 -160-5656160 -254-8484254

29. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Modifier Codebook  We created the codebook from random numbers by minimizing the error for a set of images. –Simulated Annealing –Modified version of LBG-algorithm  Symmetry was enforced to reduce on-chip memory  This way only half the table needed to be stored on chip. -8-228 -12-4412 -16-4416 -24-8824 -31-6631 -34-121234 -47-191947 -50-8850 -62-121262 -68-242468 -80-282880 -94-383894 -100-1616100 -127-4242127 -160-5656160 -254-8484254

30. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Modifier Codebook  We created the codebook from random numbers by minimizing the error for a set of images. –Simulated Annealing –Modified version of LBG-algorithm  Symmetry was enforced to reduce on-chip memory  This way only half the table needed to be stored on chip. -8-2 -12-4 -16-4 -24-8 -31-6 -34-12 -47-19 -50-8 -62-12 -68-24 -80-28 -94-38 -100-16 -127-42 -160-56 -254-84

31. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Modifier Codebook  We created the codebook from random numbers by minimizing the error for a set of images. –Simulated Annealing –Modified version of LBG-algorithm  Symmetry was enforced to reduce on-chip memory  This way only half the table needed to be stored on chip. -8-2 -12-4 -16-4 -24-8 -31-6 -34-12 -47-19 -50-8 -62-12 -68-24 -80-28 -94-38 -100-16 -127-42 -160-56 -254-84  The same table is used for all textures – can be hardwired into the logic.

32. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Bit outline  First 12 bits is RGB444 which gives the base color for the entire block. 12 bit RGB444 9956b59f 995 153 153 85

33. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Bit outline  Next 4 bits selects a table from a set of 16 tables 12 bit RGB444 9956 11100001 -8-228 -12-4412 -16-4416 -24-8824 -31-6631 -34-121234 -47-191947 -50-8850 -62-121262 -68-242468 -80-282880 -94-383894 -100-1616100 -127-4242127 -160-5656160 -254-8484254

34. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Bit outline  Next 4 bits selects a table from a set of 16 tables. 12 bit RGB444 9956 11100001 -47-191947 11100001 -8-228 -12-4412 -16-4416 -24-8824 -31-6631 -34-121234 -47-191947 -50-8850 -62-121262 -68-242468 -80-282880 -94-383894 -100-1616100 -127-4242127 -160-5656160 -254-8484254

35. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Bit outline  The next 2 bits modifies the first pixel according to the table… 12 bit RGB444 9956 -47-191947 11100001 66134 = 85153 -19 + 10 4719-19 - 47

36. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Bit outline  The next 2 bits modifies the first pixel according to the table… and so on. 12 bit RGB444 9956 -47-191947 11100001 153 85 +-47 =106 38 1110

37. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Bit outline  The next 2 bits modifies the first pixel according to the table… and so on. 12 bit RGB444 9956 -47-191947 11100001 153 85 +47 =200 132 111001

38. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Bit outline  The next 2 bits modifies the first pixel according to the table… and so on. 12 bit RGB444 9956 -47-191947 11100001 153 85 +47 =200 132 111001

39. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Bit outline  The next 2 bits modifies the first pixel according to the table… and so on. 12 bit RGB444 9956 -47-191947 11100001 153 85 +-19 =134 66 111001 10

40. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Bit outline  The next 2 bits modifies the first pixel according to the table… and so on. 12 bit RGB444 9956 -47-191947 11100001 153 85 +47 =200 132 111001 1001

41. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Bit outline  The next 2 bits modifies the first pixel according to the table… and so on. 12 bit RGB444 9956 -47-191947 11100001 153 85 +-47 =106 38 111001 100111

42. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Bit outline  The next 2 bits modifies the first pixel according to the table… and so on. 12 bit RGB444 9956 -47-191947 11100001 153 85 +-47 =106 38 111001 100111

43. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Simple Decompression  The correct texel is selected

44. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Simple Decompression  The correct texel is selected  The modifier value is looked up

45. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Simple Decompression  The correct texel is selected  The modifier value is looked up  The base color is extended to 24 bits

46. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Simple Decompression  The correct texel is selected  The modifier value is looked up  The base color is extended to 24 bits  The modifier value is added

47. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Simple Decompression  The correct texel is selected  The modifier value is looked up  The base color is extended to 24 bits  The modifier value is added  The result is clamped

48. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt PACKMAN Flaws  PACKMAN was of very low complexity, but –2 dB worse than DXTC in terms of Peak Signal to Noise Ratio (PSNR) –Suffered from chrominance banding / block artifacts due to low color resolution (RGB444) originalPACKMAN

49. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt PACKMAN Flaws  PACKMAN was of very low complexity, but –2 dB worse than DXTC in terms of Peak Signal to Noise Ratio (PSNR) –Suffered from chrominance banding / block artifacts due to low color resolution (RGB444) originalPACKMAN

50. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Enhancing the Chrominance …would increasing the block size help?  By coding 4x4 blocks instead of 2x4 blocks, spatial redundancy could be better exploited.  The small block size of 32 bits would be lost, but that was only beneficial in systems without a texture cache, so it was not a big loss.

51. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Neighboring Base Colors Quite Similar 88% within interval [-4, 3] max(|R1-R2|, |G1-G2|, |B1-B2|) (in RGB555)

52. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Differential Encoding R GB table 111001 100111

53. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Differential Encoding R GB table

54. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Differential Encoding R GB table  Instead of coding the left block with RGB444… left block

55. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Differential Encoding R GB R GB table  Instead of coding the left block with RGB444… and the right with RGB444… left blockright block left blockright block

56. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Differential Encoding R GB R GB table R GBtable bits  Instead of coding the left block with RGB444… and the right with RGB444…  We code the left with RGB555… left blockright block left blockright block

57. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Differential Encoding R GB R GB table RdR GdGBdBtable bits  Instead of coding the left block with RGB444… and the right with RGB444…  We code the left with RGB555… and the right with dR dG dB 333. left blockright block left blockright block

58. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Differential Encoding RdR GdGBdBtable bits  However, in 10% of the cases, the left and right blocks will differ too much in color for differential coding. left blockright block

59. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Differential Encoding RdR GdGBdBtable bits  However, in 10% of the cases, the left and right blocks will differ too much in color for differential coding. left blockright block

60. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Differential Encoding RdR GdGBdBtable bits  However, in 10% of the cases, the left and right blocks will differ too much in color for differential coding.  For these blocks, we fall black to individual coding. left blockright block G GB BR R table bits

61. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Differential Encoding RdR GdGBdBtable bits  However, in 10% of the cases, the left and right blocks will differ too much in color for differential coding.  For these blocks, we fall black to individual coding.  We thus need an extra bit to signal if we are in differential mode or not. left blockright block G GB BR R table bits 555differential or 444

62. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Differential Encoding RdR GdGBdBtable bits  However, in 10% of the cases, the left and right blocks will differ too much in color for differential coding.  For these blocks, we fall black to individual coding.  We thus need an extra bit to signal if we are in differential mode or not.  We must take that bit from somewhere. left blockright block G GB BR R table bits 555differential or 444

63. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Differential Encoding RdR GdGBdBtable bits  By shrinking the codebook from 16 entries to 8, we can save one bit on each of the table code words. G GB BR R table bits -8-228 -12-4412 -16-4416 -24-8824 -31-6631 -34-121234 -47-191947 -50-8850 -62-121262 -68-242468 -80-282880 -94-383894 -100-1616100 -127-4242127 -160-5656160 -254-8484254

64. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Differential Encoding RdR GdGBdBtable bits  By shrinking the codebook from 16 entries to 8, we can save one bit on each of the table code words. G GB BR R table bits -8-228 -17-5517 -29-9929 -42-131342 -60-181860 -80-242480 -106-3333106 -183-4747183

65. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Differential Encoding RdR GdGBdBtable bits  By shrinking the codebook from 16 entries to 8, we can save one bit on each of the table code words. G GB BR R table bits -8-228 -17-5517 -29-9929 -42-131342 -60-181860 -80-242480 -106-3333106 -183-4747183

66. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Differential Encoding RdR GdGBdBtable bits  By shrinking the codebook from 16 entries to 8, we can save one bit on each of the table code words.  That creates room for an extra bit. G GB BR R table bits -8-228 -17-5517 -29-9929 -42-131342 -60-181860 -80-242480 -106-3333106 -183-4747183 flipped or non flipped

67. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Differential Encoding RdR GdGBdBtable bits  By shrinking the codebook from 16 entries to 8, we can save one bit on each of the table code words.  That creates room for an extra bit.  The new bit determines if the 2x4 blocks are vertically or horizontally oriented. G GB BR R table bits flipped or non flipped

68. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Results “improved PACKMAN” or iPACKMAN for short  Much less chrominance banding  Jumps 2.5 dB in PSNR overall PACKMANiPACKMAN

69. Slide title In CAPITALS 50 pt Slide subtitle 32 pt Compression

70. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Simple Compression  Find the base color for the two blocks  See if their RGB555 representations can be coded differentially, else use RGB444 representations  Exhaustively try all tables and all per-pixel modifiers  Very fast – around 60 milliseconds for a 128 x 128 texture

71. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Finding the Base Color  We start with the average color of the block.  Going from RGB888 to RGB555, we go from many points in RGB space… R G

72. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Finding the Base Color R G  We start with the average color of the block.  Going from RGB888 to RGB555, we go from many points in RGB space…  … to a few.

73. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Finding the Base Color R G  We start with the average color of the block.  Going from RGB888 to RGB555, we go from many points in RGB space…  … to a few.  Ordinary quantization just chooses the closest one.

74. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Finding the Base Color R G  We start with the average color of the block.  Going from RGB888 to RGB555, we go from many points in RGB space…  … to a few.  Ordinary quantization just chooses the closest one.

75. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Finding the Base Color R G  However, the per-pixel luminance modification can compensate for errors in the direction (1,1,1)  We can reach (almost) all points on the dotted lines

76. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Finding the Base Color  However, the per-pixel luminance modification can compensate for errors in the direction (1,1,1)  We can reach (almost) all points on the dotted lines R G

77. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Finding the Base Color  However, the per-pixel luminance modification can compensate for errors in the direction (1,1,1)  We can reach (almost) all points on the dotted lines  We should also try the point closest to this line. R G

78. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Finding the Base Color  However, the per-pixel luminance modification can compensate for errors in the direction (1,1,1)  We can reach (almost) all points on the dotted lines  We should also try the point closest to this line.  This is fast – 120 ms per 128x128 texture. R G

79. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt More Thorough Compression  A more thorough compression can try all the neighboring colors +/- 3 steps from the average color.  “Medium”-speed, around 20 seconds per 128x128 texture R G

80. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Even slower Compression…  Our slowest version will search 5 steps out from the average color.  About 7 minutes per 128x128 block  Exhaustive compression is also possible (as proven by Eric Fausett) R G

81. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Compression  The difference between the fastest and best compression methods is about 1.3 dB PSNR Average (60 ms) Fast (120 ms) Medium (20s) 1.3 dB Slow (7 min) Exhaustive

82. Slide title In CAPITALS 50 pt Slide subtitle 32 pt Decompression

83. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Simple HW for decompression

84. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Simple HW for decompression 6 adders

85. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Simple HW for decompression 6 adders a few MUXes

86. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Simple HW for decompression 6 adders a few MUXes 1 LUT

87. Slide title In CAPITALS 50 pt Slide subtitle 32 pt Results

88. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Quality Measure  One common measure is the Root Mean Square Error (RMSE) measure.

89. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Quality Measure  One common measure is the Root Mean Square Error (RMSE) measure.  A variant of this is Peak Signal to Noise ratio (PSNR)

90. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Quality Measure  One common measure is the Root Mean Square Error (RMSE) measure.  A variant of this is Peak Signal to Noise ratio (PSNR)  Usually, 0.25 dB difference is a visible difference.

91. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Results We have compared against the following systems: SchemeCoder Used S3TC/DXTC [Iourcha et al. ‘99]ATI’s Compressonator, with weights [1, 1, 1] to maximize PSNR

92. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Results We have compared against the following systems: SchemeCoder Used S3TC/DXTC [Iourcha et al. ‘99]ATI’s Compressonator, with weights [1, 1, 1] to maximize PSNR PVR-TC [Fenney ’03]No coder publicly available – the same images were used and results taken from the paper.

93. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Results We have compared against the following systems: SchemeCoder Used S3TC/DXTC [Iourcha et al. ‘99]ATI’s Compressonator, with weights [1, 1, 1] to maximize PSNR PVR-TC [Fenney ’03]No coder publicly available – the same images were used and results taken from the paper. The 7 images used were: Lena Lorikeet Kodim1-5

94. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Results We have compared against the following systems: SchemeCoder Used S3TC/DXTC [Iourcha et al. ‘99]ATI’s Compressonator, with weights [1, 1, 1] to maximize PSNR PVR-TC [Fenney ’03]No coder publicly available – the same images were used and results taken from the paper. PACKMAN [Strom and Akenine- Moller ’04] Exhaustive Coding

95. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Results for iPACKMAN We have compared against the following systems: SchemeCoder UsedAverage Gain S3TC/DXTC [Iourcha et al. ‘99]ATI’s Compressonator, with weights [1, 1, 1] to maximize PSNR 0.41 dB PVR-TC [Fenney ’03]No coder publicly available – the same images were used and results taken from the paper. 0.65 dB PACKMAN [Strom and Akenine- Moller ’04] Exhaustive Coding2.5 dB

96. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Strengths  The strengths can most easily be seen in areas with fine variations in luminance. original

97. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Strengths  The strengths can most easily be seen in areas with fine variations in luminance. original S3TC/DXTC

98. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Strengths  The strengths can most easily be seen in areas with fine variations in luminance. original S3TC/DXTCiPACKMAN

99. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Strengths  The strengths can most easily be seen in areas with fine variations in luminance. original S3TC/DXTCiPACKMAN

100. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Strengths  The strengths can most easily be seen in areas with fine variations in luminance. original S3TC/DXTCiPACKMAN

101. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Strengths  The strengths can most easily be seen in areas with fine variations in luminance. original S3TC/DXTCiPACKMAN

102. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Weaknesses  When there are more than two colors of different chrominance in a 2x4 block, iPACKMAN has problems.  Such artifacts are especially visible when the two colors have similar luminance.

103. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Weaknesses  When there are more than two colors of different chrominance in a 2x4 block, iPACKMAN has problems.  Such artifacts are especially visible when the two colors have similar luminance. original

104. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Weaknesses  When there are more than two colors of different chrominance in a 2x4 block, iPACKMAN has problems.  Such artifacts are especially visible when the two colors have similar luminance. original S3TC/DXTC

105. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Weaknesses  When there are more than two colors of different chrominance in a 2x4 block, iPACKMAN has problems.  Such artifacts are especially visible when the two colors have similar luminance. original S3TC/DXTCiPACKMAN

106. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Error Metric  When selecting one way to compress a block over another, an error metric is used to tell which is better.  An obvious error metric to use is to sum the squared error over the block:  e 2 = (R-R’) 2 + (G-G’) 2 + (B-B’) 2  However, since the eye is more sensitive to errors in green than in red and blue, it makes sense to add more weight to the green component:  e 2 = w R 2 (R-R’) 2 + w G 2 (G-G’) 2 + w B 2 (B-B’) 2

107. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Error Metric  Original

108. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Error Metric  Original

109. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Error Metric  Original  Non-perceptual Error Metric

110. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Error Metric  Original  Non-perceptual Error Metric  Perceptual Error Metric

111. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Error Metric  Original  Non-perceptual Error Metric  Perceptual Error Metric

112. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Error Metric  Original  Non-perceptual Error Metric  Perceptual Error Metric

113. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Error Metric  Original  Non-perceptual Error Metric  Perceptual Error Metric

114. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Error Metric  Original  Non-perceptual Error Metric  Perceptual Error Metric

115. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Normal Maps  We have tried to compress tangent space normal maps with iPACKMAN, with mixed results.  For high-frequency normal maps, such as the one to the right, it works fine.  However, for slowly varying normal maps, banding becomes a problem.  The result is that iPACKMAN should not be used for normal maps, except in high-frequency cases. original iPACKMAN

116. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Alpha (RGBA) Textures  Currently, iPACKMAN cannot handle RGBA textures.  In DXT2-5, the alpha (A-component) is treated separately from the RGB components:

117. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Alpha (RGBA) Textures  A similar method could be applicable for iPACKMAN  It is also possible to cram all four components (R, G, B and A) into 64 bits, but this will compromise image quality. 64 bits RGB64 bits A64 bits RGB64 bits A …  Currently, iPACKMAN cannot handle RGBA textures.  In DXT2-5, the alpha (A-component) is treated separately from the RGB components:

118. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Adoption  The Khronos organization has adopted iPACKMAN under the name “Ericsson Texture Compression” (ETC) through an OES extension for OpenGL ES.  Compression software source code will soon be available for download.  Independent hardware vendors have started implementing ETC.

119. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Summary  We have presented a High-Quality, Low Complexity texture compression system.  Quality is slightly better (0.4 dB) than state-of-the-art compression technology (DXTC) at the same bit rate (4 bits per pixel).  Khronos has adopted the technology through an OES extension to their popular OpenGL ES API.  Future work includes improving on the weak points, as well as handle alpha and normal data better.

120. Slide title In CAPITALS 50 pt Slide subtitle 32 pt Thank you

121. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt

122. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt PACKMAN Flaws  PACKMAN was of very low complexity, but –2 dB worse than S3TC in terms of Peak Signal to Noise Ratio (PSNR) –Suffered from chrominance banding / block artifacts due to low color resolution (RGB444) originalPACKMAN

123. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt Results “improved PACKMAN” or iPACKMAN for short  Much less chrominance banding  Jumps 2.5 dB in PSNR overall PACKMANiPACKMAN