IsBlank modifies image "in-place"

[Username]

IsBlank() modifies the image - this is unacceptable. When I pass 8 bit image to it, after execution of IsBlank and saving the image, now it is suddenly 24 bit and about 3 times bigger compared to real LZW 8 bit image. This is a very simple code that can reproduce the problem (all crazy checks for GdPictureStatus are omitted for brevity):

Code: Select all

GdPictureImaging img = new GdPictureImaging();
GdPicturePDF pdf = new GdPicturePDF();

pdf.LoadFromFile(@"C:\Input.pdf", false);
pdf.SelectPage(1);

int renderedImageId = pdf.RenderPageToGdPictureImage(300, true);
img.ConvertTo8Bpp216(renderedImageId);
// Commenting IsBlank call produces different C:\Out.tif image
img.IsBlank(renderedImageId);
img.SaveAsTIFF(renderedImageId, @"C:\Out.tif", TiffCompression.TiffCompressionLZW);

img.ReleaseGdPictureImage(renderedImageId);
img.Dispose();
pdf.CloseDocument();
pdf.Dispose();

When I execute such code, I expect that the resulting file "C:\Out.tif" will be 8 bit (because of img.ConvertTo8bpp216 call) but it is not - when I see properties for the file, it says "24 bit LZW" and in my case the file size is about 830 KB. If I comment the line that calls IsBlank and leave all other code intact, the resulting file properties are "8 bit LZW" and file size is about 340 KB.

Is it by design (modifying original image in order to determine if it is blank) or it is a bug in GdPicture ? Could it be fixed for next release and when it will happen ?

[Loïc]

Hello Username,

You are right, this is not a normal behavior. The problem has been fixed for the next 9.2.3 release.

Kind regards,

Loïc

[Username]

That was really fast response...

[Loïc]

New version available fixing the issue. See: https://www.gdpicture.com/download/downl ... urenet.php

Hope this helps!