read jpeg without quality loss

Asked Jan 05 '16 at 06:10

Active Jan 05 '16 at 06:10

Viewed 167 times

I have an jpeg image 720x480 8BPP with a quality of 95%.
If I open this image with IrfanView and type "i" to get the information to this image I can see that this image has 238 unique colors. If I open this image in C# with

Image image1 = Image.FromFile("J:\\test.jpg", true);

and count the unique colors, I always count only 16. Also when I save this image regardless of JPG or BMP, if I opend this saved image with IrfanView and look to the info I see only 16 unique colors.
What is the reason for that?

Best regards
Michael

asked Jan 05 '16 at 06:10

Michael

You can see this answer: http://stackoverflow.com/questions/13195642/losing-image-quality-in-c-sharp-using-image-class-reduces-amount-of-colors – Daniel Jo Jan 05 '16 at 06:18
I read this article but the image.LoadFrom method with second parameter = true doesn't work for me. – Michael Jan 05 '16 at 08:42
Is this a grayscale image then? 8BPP. – user3344003 Jan 05 '16 at 20:14
Yes it is. (jpeg image 720x480 8BPP with a quality of 95%) – Michael Jan 06 '16 at 05:47

read jpeg without quality loss

0 Answers0