December 03, 2020, 08:19:02 PM

### Author Topic: [bb] Image color FX by Matt Merkulov [ 1+ years ago ]  (Read 445 times)

#### BlitzBot

• Jr. Member
•  • Posts: 1 ##### [bb] Image color FX by Matt Merkulov [ 1+ years ago ]
« on: June 29, 2017, 12:28:39 AM »
Title : Image color FX
Author : Matt Merkulov
Posted : 1+ years ago

Description : From <a href="http://blitzetcetera.org/" target="_blank">Blitz et cetera[/url] article
Image used: Code :
Code: BlitzBasic
1. ;Image color FX by Matt Merkulov
2.
3. Const k# = 180.0 / 255, k2# = 360.0 / 255, fx = 2
4. Dim col(2)
5.
6. Graphics 640,480,32
7.
9. DrawBlock i, 0,0
10. For y=0 To 479
11.  For x=0 To 639
12.  p = ReadPixel (x, y)
13.  For n = 0 To 2
14.   c = p And 255
15.   p = p Shr 8
16.   Select fx
17.   Case 1; Negative
18.    c = 255 - c
19.   Case 2; Darkening
20.    c = c Shr 1
21.   Case 3; Lightening
22.    c = 128 + (c Sar 1)
23.   Case 4; Threshold
24.    c = 255 * (c >= 128)
25.   Case 5; Saturation reduction
26.    c = 64 + (c Sar 1)
27.   Case 6; Saturation increase
28.    c = c Shl 1 - 128
29.    If c < 0 Then c = 0
30.    If c > 255 Then c = 255
31.   Case 7; Square-law darkening
32.    c = 255 - Sqr(255 * 255 - c * c)
33.   Case 8; Square-law lightening
34.    c = 255 - c
35.    c = Sqr(255 * 255 - c * c)
36.   Case 9; Colors quantity reduction
37.    c = Int(c / 51) * 51
38.   Case 10; Saw
39.    c = (c Shr 6) * 4
40.   Case 11; Sawtooth
41.    If c And 64 Then c = 255 - (c And 63) * 4 Else c = (c And 63) * 4
42.   Case 12; Hollow
43.    c = 255 * (1 - Sin(c * k#))
44.   Case 13; Ledge
45.    c = 255 * Sin(c * k#)
46.   Case 14; Bend
47.    c = Sin(c * k2#) * 127 + c
48.   End Select
49.   col(n) =c
50.  Next
51.  WritePixel x, y, col(0) + col(1) Shl 8 + col(2) Shl 16 - 16777216
52.  Next
53. Next
54.
55. WaitKey

Andy_A(Posted 1+ years ago)

Thanks Matjev,The routines seem to work fine. Don't really know what "the Saw","the Hollow","the Ledge","the Bend","Zubya" mean.Try using simple words to describe then translate to English.Here's another tranlator site: <a href="http://webtranslation.imtranslator.net/" target="_blank">http://webtranslation.imtranslator.net/[/url]

Matt Merkulov(Posted 1+ years ago)

Take look at the graphs: In fact, they're just funny fx, maybe not so useful as standard.

Andy_A(Posted 1+ years ago)

They are some of the same effects used in GIMP and Photoshop. Not the same code, but same effects, so they could be useful to someone.