OpenEuphoria

Re: Load and Display a JPG Image

• Posted by ssallen Mar 03, 2013
• 1870 views

I have used CXImage in the past and it makes it pretty easy if all you want to do is draw a jpg/gif/png/etc in a window:

 
global function getImageType(sequence xbytes)  -- xbytes is first 5 bytes of file 
 
        integer imgtype 
 
		imgtype = 0 
 
        if xbytes[1] = 'ÿ' then 
                if xbytes[2] = 'Ø' and xbytes[3] = 'ÿ' then     
                        imgtype = CXI_FORMAT_JPG 
                end if 
        elsif xbytes[2] = 'P' then 
                if xbytes[3] = 'N' and xbytes[4] = 'G' then 
                        imgtype = CXI_FORMAT_PNG 
                end if                           
        elsif xbytes[1] = 66 then 
                if xbytes[2] = 77 then 
                        imgtype = CXI_FORMAT_BMP 
                end if 
        elsif xbytes[1] = 'G' then 
                if xbytes[2] = 'I' and xbytes[3] = 'F' then 
                        imgtype = CXI_FORMAT_GIF 
                end if          
 
        else 
                imgtype = CXI_FORMAT_UNKNOWN 
        end if  
                
        return imgtype 
         
end function 

atom img, fimg, imgtyp 
sequence abytes 
 
fnumb = open("myimg.jpg", "rb") 
	 
	abytes = get_bytes(fnumb, 5) 
 
close(fnumb) 
 
imgtyp = getImageType(abytes) 
 
img = CXI_LoadImage("myimg.jpg", imgtyp, 0) 
 
if img < 1 then 
	ret = message_box("Image load error!", "File is busted!", MB_OK) 
	return -1	 
end if 
	 
fimg = CXI_MakeBitmap(img, NULL) 
 
-- draw the image using whatever api you are using 
drawBitmap(Window1, fimg, 428, 308)  -- win32lib 
 
CXI_FreeImage(fimg) 
 

cxImage uses its own internal image format so make sure you use CXI_MakeBitmap - not using it will cause machine level exceptions.

Steve A.