Image processing apparatus and image forming apparatus

1. An image processing apparatus, comprising:

an image forming instructing section which notifies an image forming section, which is capable of performing a first printing processing of performing image forming with use of a plurality of colors including at least one chromatic color and a second printing processing of performing image forming with use of only black color, a printing type processing requested to be performed among the first printing processing and the second printing processing;

a data obtaining section which obtains pixel data from a plurality of pixels constituting an image;

an operating section for inputting designated color data indicating color;

a pixel data extracting section which extracts pixel data of colors, except for a designated color indicated by the designated color data inputted through the operating section, from pixel data obtained by the data obtaining section; and

a printing type selecting section which selects a printing type from among the first printing processing and the second printing processing based on each pixel data extracted by the pixel data extracting section, wherein

the image forming instructing section notifies the printing type selected by the printing type selecting section as the type of printing processing requested to be performed.

2. The image processing apparatus according to claim 1 , wherein

the designated color data and pixel data for each pixel are constituted by color component data associated with a plurality of reference color components, and

the pixel data extracting section executes processing of comparing the designated color data and the pixel data obtained by the data obtaining section for each pixel based on each reference color component, and extracts pixel data of a pixel, in which a reference color component is absent which has color component data having difference with respect to color component data of the designated color data within a predetermined range, from among the pixel data obtained by the data obtaining section.

3. The image processing apparatus according to claim 2 , wherein

the printing type selecting section (1) determines, for each pixel of the pixel data extracted by the pixel data extracting section, that the pixel is a color pixel if at least one of differences among color component data of the pixel is greater than a predetermined threshold value, and (2) determines, for each pixel line corresponding to a scanning line of the image, if the number of color pixels belonging to the pixel line is equal to or greater than a predetermined threshold value, and (3) determines that the image is a color image if the number of color pixel lines having the number of color pixels equal to or greater than the predetermined threshold value is equal to or greater than a predetermined threshold value, and (4) selects the first printing processing as the printing type.

4. The image processing apparatus according to claim 1 , wherein

the operating section includes:

a display section which displays an image; and

a touch panel which is formed to be integral with the display section and outputs a detection signal indicating a touch position if a user touches the display section, and

the image processing apparatus further comprises:

a display controller which controls the display section to display a plurality of colors as selection candidate colors in a selectable manner, and if a detection signal indicating a position of any of the plurality of the selection candidate colors displayed on the display section is outputted by the touch panel, the display controller obtaining the selection candidate color displayed on the position indicated by the detection signal as the designated color.

5. The image processing apparatus according to claim 4 , wherein

the display controller controls the display section to display the color obtained as the designated color as a temporarily set color, and controls the display section to display a button for receiving an instruction of fixing the designated color, and if a detection signal indicating a position of the button displayed on the display section is outputted by the touch panel, the temporarily set color is fixed as the designated color, and

the pixel data extracting section uses data indicating the designated color fixed by the display controller as the designated color data.

6. The image processing apparatus according to claim 5 , wherein

the display controller controls the display section to display a predetermined number of colorless boxes at a time of displaying the plurality of selection candidate colors, and when displaying the temporarily set color on the display section, a color of the box is changed to the temporarily set color to display the temporarily set color.

7. The image processing apparatus according to claim 6 , wherein

when a detection signal indicating a display position of a selection candidate color different from the temporarily set color displayed on the display section is outputted by the touch panel, the display controller changes the colorless box displayed on the display section to be a new temporarily designated color corresponding to the selection candidate color displayed at the position indicated by the detection signal.

8. An image forming apparatus, comprising:

the image processing apparatus according to claim 1 ; and

an image forming section which performs image forming operation in accordance with a type of the printing processing notified by the image forming instructing section.