Re: [GD-DEVEL] Defining JPG DPI and Bit Depth Parameters

Thanks for the prompt response.  I will take the liberty to shoot a  
couple of more questions:

1)  Does gd support Tif images, If not are there plans to add this  
feature ?

2) Is there a way to calculate the appropriate pixel dimensios of a  
jpg image by for a particular file size.  For example I would like to  
resize all images in a folder to 20 KB.

Thanks again,

Miguel Maldonado

On Jan 17, 2007, at 9:08 PM, Pierre wrote:

> Hi Miguel,
>
> On 1/18/07, Miguel Maldonado <[email protected]> wrote:
>> Hi,
>>
>> I'm new to using the gd library.  My goal is to batch resize a large
>> number of jpg images.  Using the examples in the documentation I can
>> easily reduce the size of the images but I'm not able to maintain the
>> values for the DPI and the Bit Depth for the image. While the  
>> original
>> image has a DPI of 200 and a Bit Depth of 1 the resized image has the
>> default resolution of 96 and a Bit Depth of 8.
>
> GD supports only palette (256 colors) and truecolor images (31biits
> rgba). That's why the resulting image is not 1bit anymore, it is
> transformed at load time.
>
> The dpi is a descriptive informations but does not affect the image
> contents itself. A 100x100 dot buffer will be 100x100 in the jpeg
> buffer.
>
> However it is useful to be able to keep the meta data while loading an
> image. I will try to provide some basic functions in 2.1.0.
>
> I hope I answered your questions.
>
> Cheers,
> --Pierre