Colour values form a bitmap

[MS]

I need to determine CMYK values from bitmaps. Is there a way in VB or Access
to do this?

The reason is that I need to determin the relative CMYK values.

Example: A square with the bottom half filled with black would have a black
value of 50%. The same square with the bottom half filled with red would
have values C=0, M=50%, Y=50%, K=0 and so on.

At the moment we're putting a small version of the image into a paint
program, flattening it (or "infinitely" blurring it) and sampling the
resulting colour and manually extracting the CMYK values from that.

This is clumsy, and time consuming requiring manual entry of the figures -
it'd be great if there was a way to automate the process and then enter the
CMYK density values into a data base for each image.

Any ideas?

[James Fortune]

"MS" <Em***@Myemail.com> wrote in message news:<Xl*******************@news-server.bigpond.net.au>...

I need to determine CMYK values from bitmaps. Is there a way in VB or Access
to do this?

The reason is that I need to determin the relative CMYK values.

Example: A square with the bottom half filled with black would have a black
value of 50%. The same square with the bottom half filled with red would
have values C=0, M=50%, Y=50%, K=0 and so on.

At the moment we're putting a small version of the image into a paint
program, flattening it (or "infinitely" blurring it) and sampling the
resulting colour and manually extracting the CMYK values from that.

This is clumsy, and time consuming requiring manual entry of the figures -
it'd be great if there was a way to automate the process and then enter the
CMYK density values into a data base for each image.

Any ideas?

I've not had to deal with CMYK values yet, but I posted code to this
NG entitled "VBA code to extract PDF stream from BMP (long)" on Mar
18, 2004 that grabs the RGB data from a bmp file. The PDF Reference
v. 1.5 pp. 242-243 talks about a Tint Transformation Function that may
enable you to convert the RGB values into CMYK format. It sounds like
you do not need to use the hexidecimal values required for PDF streams
so you can use the raw values.

James A. Fortune

[MS]

"James Fortune" <ja******@oakland.edu> wrote in message
news:a6**************************@posting.google.c om...

"MS" <Em***@Myemail.com> wrote in message

news:<Xl*******************@news-server.bigpond.net.au>...

I need to determine CMYK values from bitmaps. Is there a way in VB or Access to do this?

The reason is that I need to determin the relative CMYK values.

Example: A square with the bottom half filled with black would have a black value of 50%. The same square with the bottom half filled with red would
have values C=0, M=50%, Y=50%, K=0 and so on.

At the moment we're putting a small version of the image into a paint
program, flattening it (or "infinitely" blurring it) and sampling the
resulting colour and manually extracting the CMYK values from that.

This is clumsy, and time consuming requiring manual entry of the figures - it'd be great if there was a way to automate the process and then enter the CMYK density values into a data base for each image.

Any ideas?

I've not had to deal with CMYK values yet, but I posted code to this
NG entitled "VBA code to extract PDF stream from BMP (long)" on Mar
18, 2004 that grabs the RGB data from a bmp file. The PDF Reference
v. 1.5 pp. 242-243 talks about a Tint Transformation Function that may
enable you to convert the RGB values into CMYK format. It sounds like
you do not need to use the hexidecimal values required for PDF streams
so you can use the raw values.

James A. Fortune

Thank you.

I'll check that out.

Cheers!

[James Fortune]

"MS" <Em***@Myemail.com> wrote in message news:<N_*******************@news-server.bigpond.net.au>...

"James Fortune" <ja******@oakland.edu> wrote in message
news:a6**************************@posting.google.c om...

"MS" <Em***@Myemail.com> wrote in message

news:<Xl*******************@news-server.bigpond.net.au>...

I need to determine CMYK values from bitmaps. Is there a way in VB or Access to do this?

The reason is that I need to determin the relative CMYK values.

Example: A square with the bottom half filled with black would have a black value of 50%. The same square with the bottom half filled with red would
have values C=0, M=50%, Y=50%, K=0 and so on.

At the moment we're putting a small version of the image into a paint
program, flattening it (or "infinitely" blurring it) and sampling the
resulting colour and manually extracting the CMYK values from that.

This is clumsy, and time consuming requiring manual entry of the figures - it'd be great if there was a way to automate the process and then enter the CMYK density values into a data base for each image.

Any ideas?

I've not had to deal with CMYK values yet, but I posted code to this
NG entitled "VBA code to extract PDF stream from BMP (long)" on Mar
18, 2004 that grabs the RGB data from a bmp file. The PDF Reference
v. 1.5 pp. 242-243 talks about a Tint Transformation Function that may
enable you to convert the RGB values into CMYK format. It sounds like
you do not need to use the hexidecimal values required for PDF streams
so you can use the raw values.

James A. Fortune

Thank you.

I'll check that out.

Cheers!

After writing that code I came across the following book:

Print Programming in Windows
Potts, Jeff
CMP Books
2000
ISBN: 0879305851

He has lots of code in both VB and C to deal with printing. His code
is quite a bit more elegant than mine. He has some examples that
relate to bmp files. The only thing I didn't like about the book was
that the Printers collection available in VB is not available in
earlier versions of VBA :-(.

James A. Fortune