An image forming apparatus and an image forming method are provided. The image forming apparatus includes a processor, and each of the processor of the image forming apparatus and the image forming method includes obtaining an output image of a primary color and a secondary color that is formed on a recording medium based on an image having an area ratio of each toner being uniform over the recording medium, obtaining spectral reflectance of the output image in a main scanning direction, obtaining spectral reflectance of a primary-color solid-fill image and the recording medium stored in a memory, calculating fluctuations in area ratio of each toner of a streaked area of the output image using the spectral reflectance of the streaked area and a streak-free area of the output image, and correcting an area ratio of each toner in the streaked area of image data to be output.