It crashes when there's an invalid file selected. It gives out error: 6. and then sayonara !

Hmm, works well.. Out of interest - what is pcx still used for? I see one of those images is from Prince of Persia? or did you just convert that from another format..

Also thought it would be worth mentioning.. Gimp (open source image editor) supports PCX.. however, it fails on t4, exiting with: "Unusual PCX Flavour, giving up" - You could always submit a patch to them to add the support for that format (although you'd probably have to convert it to C.. ).

; $$$$$$$$$$$$$$$ Z77 ASM LIBRARY $$$$$$$$$$$$$$$$
; *************** SUNGOD SOFTWARE ****************
; ??????????????????? TGA.INC ????????????????????

tga.header db 18 dup(0)

tga.pal  equ byte [tga.header+1]
tga.type equ byte [tga.header+2]
tga.w    equ word [tga.header+12]
tga.h    equ word [tga.header+14]
tga.bpp  equ byte [tga.header+16]

tga.ext db '.tga', 0

; load 24BPP .TGA to 32BPP image/p. if success,
; return allocated image address in eax and w/h
; in ecx/edx. return 0 if error. in this case,
; "image" is the raw linear 32BPP pixel data

; void *load_tga(char *file);

command load.tga, file
locals image, p, bpp,\
x, y, w, h, n, row
open [file]         ; open and read header...
fail .error
read tga.header, 18
cmp tga.bpp, 24     ; verify bpp
jne .error
cmp tga.pal, NO     ; no palette
jne .error
cmp tga.type, 2     ; RGB only
jne .error
movsx ecx, tga.w    ; dimensions. 16BIT each
movsx edx, tga.h
let [w]=ecx,\       ; size in bytes=w*h*4
[h]=edx, ecx*edx,\
ecx<<2, [n]=ecx
allocate ecx        ; allocate image pointer
fail .error
let [image]=eax,\   ; data
ecx=18,\            ; offset=18+1st byte
cl+[tga.header]
seek ecx            ; read image pixels...
.loop [y]=0 to [h]
  let ecx=[h],\       ; row=h-y-1 (upside down)
  ecx-[y], ecx-1,\
  [row]=ecx,\
  ecx*[w], ecx<<2,\   ; ecx=row*w*4
  eax=[image],\       ; line address =
  eax+ecx, [p]=eax    ; &(image+(h-y-1)*w*4)
  .loop [x]=0 to [w]
    let eax=[p],\
    dword [eax]=0
    read [p], 3       ; read BGR24 as RGB24
    add [p], 4        ; advance pointer
  .endl
.endl
close
let eax=[image],\   ; return image
ecx=[w], edx=[h]    ; and w/h in ecx/edx
jmp .r
.error: error E.FILE
.r0: let eax=0
close
.r:
endc

; save 32BPP image as 24BPP .TGA

; int save_tga(char *file, void *image, int w, int h);

command save.tga, file, image, w, h
locals p, x, y, row
create [file]
fail .error
let ecx=[w], tga.w=cx,\
ecx=[h], tga.h=cx
write tga.header, 18
let eax=[image],\
[p]=eax             ; write image pixels...
.loop [y]=0 to [h]
  let ecx=[h],\
  ecx-[y], ecx-1,\   ; row=h-y-1 (upside down)
  [row]=ecx,\
  ecx*[w], ecx<<2,\  ; line address =
  eax=[image],\      ; &(image+(h-y-1)*w*4)
  eax+ecx, [p]=eax
  .loop [x]=0 to [w]
    write [p], 3     ; read BGR24 as RGB24
    add [p], 4       ; advance pointer
  .endl
.endl
close
let eax=1
jmp @f
.error: let eax=0
@@:
endc

; save vga/screen as .TGA. see DRAW.INC. this is
; slow due to repetitive read/write API calls
; for each pixel. just one 1024x768x32 screen
; is 786,432*4 = 3,145,728 bytes!

command screenshot, file
save.tga [file], [vga], [screen.w], [screen.h]
endc
    

* 0.RRRRRGGGGGBBBBB - Uncompressed 15BPP pixel
* 10.NNNNNN - Repeat previous color 6BIT (0-63) # times
* 11.NNNNNNNNNNNNNN - Repeat previous color 14BIT (0-16K) # times
    

For the best RLE compression, you can store pixels as 16BPP in files then use leftmost BIT/s for compression and remaining BITs for RGB15 or N:

Code:

* 0.RRRRRGGGGGBBBBB - Uncompressed 15BPP pixel
* 10.NNNNNN - Repeat previous color 6BIT (0-63) # times
* 11.NNNNNNNNNNNNNN - Repeat previous color 14BIT (0-16K) # times