Direct Bitmap reading

[Petr]

Hi.
This program shows a small part of what _LOADIMAGE  do when reading BMP files. The program will appear without the _LOADIMAGE command. Read BMP images in 1-bit, 4-bit, 8-bit and 24-bit formats. It's just for information for those who wonder how to load the BMP file without the LOADIMAGE command. I've figured out how to fix reading CUR files, which is exactly what I'm going to do now.

Code: QB64: [Select]

1. 'program try load 1 bit (2 color) / 4 bit (16 color) / 8 bit (256 color) / 24 bit BMP picture without _LOADIMAGE:
2. 'i writed it, because i am interested about it...    Petr
3. 'some images are viewed correctly, some not with the same program. I am sorry, but i do not know why.
4. 'all knowledge for writing this program so as it now is, i read from english wikipedia (Czech contains not enought informations). I found, that some
5. 'records in english wikipedia are not correctly and then muss reapiring some head types in this program to work.....
6. 'not writed for speed. Just for fun.
7.  
8. 'UPGRADED: Repaired bug reading 1bit / 4 bit BMPs. X axis muss be dividible by 4! So if X pointer is already so big as is image width, but is not
9. 'dividible by 32 (4 bytes x 8 bites), then CAN NOT BE RESTARTED BACK TO 0! Only if is X MOD 32 = 0 AND X >= image WIDTH, then can be X restarted back
10. 'to zero. I have read about this attribute on the Czech forums about BMP format, this is not even neited writed in english wikipedia.
11.  
12. 'I can add support for 32 bit BMPs if you send me some picture in this format.
13.  
14. S:
15. runit = runit + 1
16. SELECT CASE runit
17.     CASE 1:
18.         PRINT "Opening Black/White, 1bit recorded BMP file kitten1.BMP"
19.         file$ = "kitten1.bmp"
20.     CASE 2:
21.         PRINT "Opening 16 color BMP file kitten4.BMP"
22.         file$ = "kitten4.bmp"
23.     CASE 3:
24.         PRINT "Opening 256 color BMP file kitten8.BMP"
25.         file$ = "kitten8.bmp"
26.     CASE 4:
27.         PRINT "Opening 24bit (hi color) BMP file kitten24.BMP"
28.         file$ = "kitten24.bmp"
29.     CASE 5:
30.         PRINT "Opening 1bit (2 colors) BMP file MONKEY1.BMP"
31.         file$ = "monkey1.bmp"
32.     CASE 6:
33.         PRINT "Opening 16 color file MONKEY16.BMP"
34.         file$ = "monkey16.bmp"
35.     CASE 7:
36.         PRINT "Opening 256 color file MONKEY256.BMP"
37.         file$ = "monkey256.bmp"
38.     CASE 8: PRINT "Opening 24bit file MONKEY.BMP"
39.         file$ = "monkey.bmp"
40.     CASE 9: PRINT "End."
41.         SLEEP 2
42.         SYSTEM
43. END SELECT
44. SLEEP 2
45.  
46. TYPE BMP
47.     id AS STRING * 2
48.     size AS LONG
49.     res1 AS INTEGER
50.     res2 AS INTEGER
51.     offset AS LONG
52.     'bitmapfileheader end
53.  
54.     headersize AS LONG '12 bytes
55.     width AS LONG
56.     height AS LONG
57.     planes AS INTEGER 'always 1
58.     bpp AS INTEGER 'bits per pixel
59.     crc AS LONG 'compression if is used
60.     imgSize AS LONG ' image data block size
61.     hr AS LONG 'horizontal resolution in pixels / meter
62.     vr AS LONG 'vertical resolution in pixels / meter
63.     numPalClrs AS LONG ' number of colors in color palette
64.     impClr AS LONG 'number of important colors used or 0
65. END TYPE
66.  
67. DIM SHARED BMP AS BMP, x AS INTEGER, y AS INTEGER, PA AS LONG, PB AS LONG, PC AS LONG
68. IF _FILEEXISTS(file$) THEN OPEN file$ FOR BINARY AS #1 ELSE PRINT "File "; UCASE$(file$); " not exist.": SLEEP 3: END
69. GET #1, , BMP
70.  
71.  
72. SELECT CASE BMP.bpp
73.     CASE 24: C = 32
74.     CASE 8: C = 256: Looop = 255
75.     CASE 4: C = 256: Looop = 3
76.     CASE 1: C = 256: Looop = 1
77. END SELECT
78.  
79. m& = _NEWIMAGE(BMP.width, BMP.height, C)
80. IF BMP.bpp <= 8 THEN
81.     FOR LoadPalette = 0 TO Looop
82.         GET #1, , PA
83.         _PALETTECOLOR LoadPalette, PA, m&
84.     NEXT
85. END IF
86.  
87. PRINT "File size returned with LOF:"; LOF(1)
88. PRINT "File identity:"; BMP.id$
89. PRINT "File size writed in file:"; BMP.size
90. PRINT "Image data start offset:"; BMP.offset
91. PRINT "Header size in bytes:"; BMP.headersize
92. PRINT "Image width:"; BMP.width
93. PRINT "Image height:"; BMP.height
94. PRINT "Planes:"; BMP.planes
95. PRINT "Bites per pixel:"; BMP.bpp
96. PRINT "Compression: "; BMP.crc
97. PRINT "Image size: "; BMP.imgSize
98. PRINT "Vertical resolution: (px/M) "; BMP.vr
99. PRINT "Horizontal resolution: (px/M) "; BMP.hr
100. PRINT "Number colors in palette: "; BMP.numPalClrs
101. PRINT "Number of important colors used: "; BMP.impClr
102. PRINT "Reserved 1: "; BMP.res1
103. PRINT "Reserved 2: "; BMP.res2
104.  
105. PRINT "Current position:"; SEEK(1)
106. PRINT
107. PRINT "Press any key"
108. SLEEP
109. SCREEN m&: _FULLSCREEN
110.  
111. x = 1: y = BMP.height
112. SEEK #1, BMP.offset + 1
113. SA = SEEK(1)
114.  
115. DO WHILE NOT EOF(1)
116.     SELECT CASE BMP.bpp
117.  
118.         CASE 1 'B/W pictures
119.             IF y = 0 THEN y = BMP.height - 1
120.             REDIM clr1 AS STRING * 4
121.             clr1$ = SPACE$(4)
122.             GET #1, , clr1$
123.             binary$ = ""
124.             FOR all = 1 TO 4
125.                 binary$ = binary$ + DECtoBIN$(ASC(clr1$, all))
126.             NEXT all
127.  
128.             FOR drw = 1 TO LEN(binary$)
129.                 commnd$ = MID$(binary$, drw, 1)
130.                 IF commnd$ = "1" THEN PSET (x, y)
131.                 x = x + 1
132.                 IF x >= BMP.width THEN
133.                     IF x MOD 32 = 0 THEN x = 0: y = y - 1
134.                 END IF
135.             NEXT drw
136.  
137.         CASE 4 '16 color bitmap
138.             IF y = 0 THEN y = BMP.height - 1
139.  
140.             REDIM clr4 AS STRING * 4
141.             clr4$ = SPACE$(4)
142.             GET #1, , clr4$
143.             binary$ = ""
144.             FOR all = 1 TO 4
145.                 binary$ = binary$ + DECtoBIN$(ASC(clr4, all))
146.             NEXT all
147.  
148.             FOR SET = 1 TO LEN(binary$) STEP 4
149.                 value$ = MID$(binary$, SET, 4)
150.                 clr = BINtoDEC(value$)
151.                 PSET (x, y), clr
152.                 x = x + 1: IF x >= BMP.width THEN
153.                     IF x MOD 32 / 4 = 0 THEN x = 0: y = y - 1
154.                 END IF
155.             NEXT SET
156.  
157.  
158.         CASE 8 '256 color bitmap
159.             IF y = 0 THEN y = BMP.height - 1
160.             REDIM clr AS STRING * 1
161.             GET #1, , clr
162.             PSET (x, y), ASC(clr)
163.             x = x + 1: IF x >= BMP.width THEN
164.                 IF x MOD 4 = 0 THEN
165.                     x = 0: y = y - 1
166.                 END IF
167.             END IF
168.             '            PSET (x, y), ASC(clr)
169.  
170.         CASE 24 '24 bit bitmap
171.             IF y = 0 THEN y = BMP.height - 1
172.             REDIM cl AS STRING * 3
173.             GET #1, , cl
174.             b = ASC(cl, 1)
175.             g = ASC(cl, 2)
176.             r = ASC(cl, 3)
177.  
178.  
179.             x = x + 1
180.             IF x >= BMP.width THEN
181.                 IF x MOD 4 = 0 THEN
182.                     x = 0: y = y - 1
183.                 END IF
184.             END IF
185.             PSET (x, y), _RGB32(r, g, b)
186.     END SELECT
187. LOOP
188. SLEEP 3
189. SCREEN 0
190. _FREEIMAGE m&
191. CLOSE #1
192. CLS
193. GOTO S
194.  
195.  
196.  
197.  
198. FUNCTION DECtoBIN$ (vstup)
199.     FOR rj = 7 TO 0 STEP -1
200.         IF vstup AND 2 ^ rj THEN DECtoBIN$ = DECtoBIN$ + "1" ELSE DECtoBIN$ = DECtoBIN$ + "0"
201.     NEXT rj
202. END FUNCTION
203.  
204. FUNCTION BINtoDEC (b AS STRING)
205.     FOR Si = 1 TO LEN(b)
206.         e$ = MID$(b$, Si, 1)
207.         c = VAL(e$) '
208.         Sj = LEN(b) - Si
209.         BINtoDEC = BINtoDEC + (c * 2 ^ Sj)
210.     NEXT Si
211. END FUNCTION
212.