[sane-devel] Basic Image Buffering

[dio.rahman at gmail.com]

yeah -- it works; I use OpenCV to buffer the image -- with the size
the same as the param.pixels_per_line * param.line (width * height)



On 2/3/09, m. allan noah <kitno455 at gmail.com> wrote:
> but when you use scanimage, it works?
>
> what image format are you saving it as?
>
> allan
>
> On Mon, Feb 2, 2009 at 8:41 PM,  <dio.rahman at gmail.com> wrote:
>> it's unsigned char
>> (unsigned char * imageData)
>>
>> as you can see in the scanimage example, in each loop the sane_read
>> will put the data into buffer with the specific buffer_size and actual
>> data length (len). Hence, in each loop we have to copy that "partial
>> image data" and assembly that data into the imageData.
>>
>> I also used that 'memcpy'
>>
>> while(status != SANE_STATUS_EOF){
>>                                status = sane_read (device, buffer,
>> buffer_size, &len);
>>
>>                                memcpy(imageData+offset,buffer,len);
>>                                offset+=len;
>>
>>                                 .....
>>
>> }
>>
>> and the problem still the same.
>>
>> Dio
>>
>>
>>
>>
>>
>> On 2/3/09, m. allan noah <kitno455 at gmail.com> wrote:
>>> what data type is imageData? why not memcpy instead?
>>>
>>> allan
>>>
>>> On Mon, Feb 2, 2009 at 7:43 PM,  <dio.rahman at gmail.com> wrote:
>>>> Dear all,
>>>>
>>>> I have a basic question on buffering the image.
>>>>
>>>> Suppose I have an image data pointer * imageData; and I have image
>>>> dimension information i.e. width and height.
>>>>
>>>> I need to copy the bytes read from the scanning process i.e. in the
>>>> buffer (sane_read(buffer,buffer_size,&len)) to the image data.
>>>>
>>>> So, I do:
>>>>
>>>> for(int i=0;i<len;i++)
>>>>    *(imageData++) = buffer[i]
>>>> until I found the SANE_STATUS_EOF
>>>>
>>>> but, when I showed the image, the pixel is not in the right order;
>>>> Anyone can help me?
>>>>
>>>> Thanks
>>>>
>>>> Dio
>>>> NOTE: I'm using CanonScan LiDE 50 -- grayscale image; and doing find
>>>> with the scanimage example
>>>>
>>>> --
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>>>>
>>>
>>>
>>>
>>> --
>>> "The truth is an offense, but not a sin"
>>>
>>
>
>
>
> --
> "The truth is an offense, but not a sin"
>